Form N-Q

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, DC 20549

FORM N-Q


QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED MANAGEMENT INVESTMENT COMPANY

Investment Company Act file number         811-06379         

        Nuveen Insured Municipal Opportunity Fund, Inc.         
(Exact name of registrant as specified in charter)

Nuveen Investments
        333 West Wacker Drive, Chicago, Illinois 60606         

(Address of principal executive offices) (Zip code)


Kevin J. McCarthy Vice President and Secretary
        333 West Wacker Drive, Chicago, Illinois 60606         

(Name and address of agent for service)

Registrant's telephone number, including area code:         312-917-7700        

Date of fiscal year end:            10/31          

Date of reporting period:         1/31/09         

Form N-Q is to be used by management investment companies, other than small business investment companies registered on Form N-5 (§§ 239.24 and 274.5 of this chapter), to file reports with the Commission, not later than 60 days after the close of the first and third fiscal quarters, pursuant to rule 30b1-5 under the Investment Company Act of 1940 (17 CFR 270.30b1-5). The Commission may use the information provided on Form N-Q in its regulatory, disclosure review, inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N-Q, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-Q unless the Form displays a currently valid Office of Management and Budget ("OMB") control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to the Secretary, Securities and Exchange Commission, 450 Fifth Street, NW, Washington, DC 20549-0609. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. § 3507.

Item 1. Schedule of Investments

    Portfolio of Investments (Unaudited)             
    Nuveen Insured Municipal Opportunity Fund, Inc. (NIO)             
    January 31, 2009             
Principal        Optional Call         
Amount (000)    Description (1)    Provisions (2)    Ratings (3)    Value 

    Alabama – 6.0% (3.8% of Total Investments)             
$     3,500    Birmingham Waterworks And Sewer Board, Alabama, Water and Sewer Revenue Bonds, Tender    1/17 at 100.00    A3   $   1,912,260 
     Option Bond Trust 2707, 10.205%, 1/01/43 – AMBAC Insured (IF)             
11,175    Hoover Board of Education, Alabama, Capital Outlay Tax Anticipation Warrants, Series 2001,    2/11 at 100.00    AA    11,501,310 
     5.250%, 2/15/22 – MBIA Insured             
2,500    Jefferson County, Alabama, Sewer Revenue Capital Improvement Warrants, Series 2002B, 5.125%,    8/12 at 100.00    AAA    2,746,550 
     2/01/42 (Pre-refunded 8/01/12) – FGIC Insured             
    Jefferson County, Alabama, Sewer Revenue Capital Improvement Warrants, Series 2002D:             
425     5.000%, 2/01/38 (Pre-refunded 8/01/12) – FGIC Insured    8/12 at 100.00    AAA    461,240 
14,800     5.000%, 2/01/42 (Pre-refunded 8/01/12) – FGIC Insured    8/12 at 100.00    AAA    16,197,564 
18,760    Jefferson County, Alabama, Sewer Revenue Capitol Improvement Warrants, Series 2001A, 5.000%,    2/11 at 101.00    AAA    19,944,882 
     2/01/41 (Pre-refunded 2/01/11) – FGIC Insured             
10,195    Jefferson County, Alabama, Sewer Revenue Refunding Warrants, Series 1997A, 5.375%, 2/01/27 –    4/09 at 100.00    Caa1    5,128,799 
     FGIC Insured             
5,240    Jefferson County, Alabama, Sewer Revenue Refunding Warrants, Series 2003B, 5.000%, 2/01/41    2/11 at 101.00    AAA    5,603,027 
     (Pre-refunded 2/01/11) – FGIC Insured             

66,595    Total Alabama            63,495,632 

    Alaska – 1.3% (0.8% of Total Investments)             
2,425    Alaska Housing Finance Corporation, Collateralized Veterans Mortgage Program Bonds, First    12/09 at 100.00    AAA    2,434,530 
     Series 1999A-1, 6.150%, 6/01/39             
11,245    Alaska Housing Finance Corporation, General Mortgage Revenue Bonds, Series 1999A, 6.050%,    6/09 at 100.00    AAA    11,257,707 
     6/01/39 – MBIA Insured             

13,670    Total Alaska            13,692,237 

    Arizona – 2.3% (1.4% of Total Investments)             
    Arizona State University, Certificates of Participation, Resh Infrastructure Projects,             
    Series 2005A:             
2,000     5.000%, 9/01/25 – AMBAC Insured    3/15 at 100.00    AA–    2,002,000 
2,000     5.000%, 9/01/27 – AMBAC Insured    3/15 at 100.00    AA–    1,954,940 
1,000    Arizona State University, System Revenue Bonds, Series 2005, 5.000%, 7/01/27 – AMBAC Insured    7/15 at 100.00    A    1,004,320 
1,000    Maricopa County Union High School District 210, Phoenix, Arizona, General Obligation Bonds,    7/14 at 100.00    AAA    1,172,130 
     Series 2004A, 5.000%, 7/01/22 (Pre-refunded 7/01/14) – FSA Insured             
5,200    Mesa, Arizona, Utility System Revenue Bonds, Reset Option Longs, Series 11032- 11034, 11.539%,    7/17 at 100.00    AAA    2,266,264 
     7/01/31 – FSA Insured (IF)             
1,150    Phoenix Civic Improvement Corporation, Arizona, Junior Lien Wastewater System Revenue Bonds,    7/14 at 100.00    AA+    1,159,177 
     Series 2004, 5.000%, 7/01/27 – MBIA Insured             
13,490    Phoenix Civic Improvement Corporation, Arizona, Junior Lien Water System Revenue Bonds, Series    7/15 at 100.00    AAA    13,574,852 
     2005, 4.750%, 7/01/25 – MBIA Insured             
1,350    Pima County Industrial Development Authority, Arizona, Lease Obligation Revenue Refunding    7/09 at 100.00    Aa3    1,359,693 
     Bonds, Tucson Electric Power Company, Series 1988A, 7.250%, 7/15/10 – FSA Insured             

27,190    Total Arizona            24,493,376 

    Arkansas – 0.3% (0.2% of Total Investments)             
3,660    Arkansas State University, Student Fee Revenue Bonds, Beebe Campus, Series 2006, 5.000%,    9/15 at 100.00    Baa1    3,070,337 
     9/01/35 – AMBAC Insured             

    California – 32.0% (20.1% of Total Investments)             
5,600    Alameda Corridor Transportation Authority, California, Subordinate Lien Revenue Bonds, Series    No Opt. Call    A    2,903,096 
     2004A, 0.000%, 10/01/20 – AMBAC Insured             
10,000    California Department of Veterans Affairs, Home Purchase Revenue Bonds, Series 2002A, 5.300%,    6/12 at 101.00    Aa2    10,404,900 
     12/01/21 – AMBAC Insured             
    California Department of Water Resources, Power Supply Revenue Bonds, Series 2002A:             
30,000     5.375%, 5/01/17 (Pre-refunded 5/01/12) – SYNCORA GTY Insured    5/12 at 101.00    Aaa    34,318,498 
25,000     5.375%, 5/01/18 (Pre-refunded 5/01/12) – AMBAC Insured    5/12 at 101.00    Aaa    28,598,748 
    California Department of Water Resources, Water System Revenue Bonds, Central Valley Project,             
    Series 2005AC:             
30     5.000%, 12/01/24 (Pre-refunded 12/01/14) – MBIA Insured    12/14 at 100.00    AAA    35,580 
25     5.000%, 12/01/27 (Pre-refunded 12/01/14) – MBIA Insured    12/14 at 100.00    AAA    29,650 
    California Department of Water Resources, Water System Revenue Bonds, Central Valley Project,             
    Series 2005AC:             
3,670     5.000%, 12/01/24 – MBIA Insured    12/14 at 100.00    AAA    3,776,320 
2,795     5.000%, 12/01/27 – MBIA Insured    12/14 at 100.00    AAA    2,828,652 
10,150    California, General Obligation Bonds, Series 2004, 5.000%, 6/01/31 – AMBAC Insured    12/14 at 100.00    A1    9,402,859 
3,500    Coachella Valley Unified School District, Riverside County, California, General Obligation    8/15 at 100.00    AA    3,463,775 
     Bonds, Series 2005A, 5.000%, 8/01/26 – FGIC Insured             
20,000    Cucamonga County Water District, San Bernardino County, California, Certificates of    9/11 at 101.00    AA–    17,425,600 
     Participation, Water Shares Purchase, Series 2000, 5.125%, 9/01/35 – FGIC Insured             
5,750    East Bay Municipal Utility District, Alameda and Contra Costa Counties, California, Water    6/15 at 100.00    AA+    5,805,545 
     System Subordinated Revenue Bonds, Series 2005A, 5.000%, 6/01/27 – MBIA Insured             
10,000    Golden State Tobacco Securitization Corporation, California, Tobacco Settlement Asset-Backed    6/15 at 100.00    A    7,968,200 
     Revenue Bonds, Series 2005A, 5.000%, 6/01/38 – FGIC Insured             
1,520    Hayward Redevelopment Agency, California, Downtown Redevelopment Project Tax Allocation    3/16 at 100.00    A–    1,283,762 
     Bonds, Series 2006, 5.000%, 3/01/36 – SYNCORA GTY Insured             
5,600    Kern Community College District, California, General Obligation Bonds, Series 2006, 0.000%,    No Opt. Call    AAA    2,385,208 
     11/01/24 – FSA Insured             
5,000    Long Beach Bond Financing Authority, California, Lease Revenue Refunding Bonds, Long Beach    11/11 at 101.00    A    3,977,550 
     Aquarium of the South Pacific, Series 2001, 5.250%, 11/01/30 – AMBAC Insured             
2,740    Los Angeles Harbors Department, California, Revenue Bonds, Series 2006A, 5.000%, 8/01/22 –    8/16 at 102.00    AA    2,562,256 
     FGIC Insured (Alternative Minimum Tax)             
20,000    Los Angeles Unified School District, California, General Obligation Bonds, Series 2003A,    7/13 at 100.00    AAA    20,761,200 
     5.000%, 7/01/21 – FSA Insured             
3,000    Los Angeles Unified School District, California, General Obligation Bonds, Series 2006F,    7/16 at 100.00    AA–    3,025,770 
     5.000%, 7/01/24 – FGIC Insured             
6,205    Port of Oakland, California, Revenue Bonds, Series 2002L, 5.000%, 11/01/22 – FGIC Insured    11/12 at 100.00    AA    5,462,324 
     (Alternative Minimum Tax)             
    Poway Redevelopment Agency, California, Tax Allocation Bonds, Paguay Redevelopment Project,             
    Series 2001:             
15,000     5.200%, 6/15/30 – AMBAC Insured    12/11 at 101.00    A    12,314,550 
5,000     5.125%, 6/15/33 – AMBAC Insured    12/11 at 101.00    A    3,934,950 
2,035    Redding, California, Electric System Revenue Certificates of Participation, Series 2005,    6/15 at 100.00    AA–    1,687,198 
     5.000%, 6/01/30 – FGIC Insured             
6,000    Redlands Unified School District, San Bernardino County, California, General Obligation Bonds,    7/13 at 100.00    AAA    6,009,180 
     Series 2003, 5.000%, 7/01/26 – FSA Insured             
2,970    Riverside Community College District, California, General Obligation Bonds, Series 2005,    8/15 at 100.00    AAA    3,127,291 
     5.000%, 8/01/22 – FSA Insured             
2,500    Sacramento County Sanitation District Financing Authority, California, Revenue Bonds, Series    12/15 at 100.00    AA    2,589,100 
     2005B, 4.750%, 12/01/21 – FGIC Insured             
13,710    San Francisco Airports Commission, California, Revenue Refunding Bonds, San Francisco    5/11 at 100.00    AA    12,049,856 
     International Airport, Second Series 2001, Issue 27A, 5.250%, 5/01/26 – MBIA Insured             
     (Alternative Minimum Tax)             
3,030    San Francisco Bay Area Rapid Transit District, California, Sales Tax Revenue Bonds, Series    7/11 at 100.00    AA+    2,992,489 
     2001, 5.125%, 7/01/36 – AMBAC Insured             
8,470    San Francisco Bay Area Rapid Transit District, California, Sales Tax Revenue Bonds, Series    7/11 at 100.00    AA+ (4)    9,314,798 
     2001, 5.125%, 7/01/36 (Pre-refunded 7/01/11) – AMBAC Insured             
1,220    San Francisco Bay Area Rapid Transit District, California, Sales Tax Revenue Bonds, Series    7/15 at 100.00    AA+    1,281,732 
     2005A, 5.000%, 7/01/22 – MBIA Insured             
66,685    San Joaquin Hills Transportation Corridor Agency, Orange County, California, Senior Lien Toll    No Opt. Call    AAA    43,279,229 
     Road Revenue Bonds, Series 1993, 0.000%, 1/01/21 (ETM)             
    San Joaquin Hills Transportation Corridor Agency, Orange County, California, Toll Road Revenue             
    Refunding Bonds, Series 1997A:             
31,615     5.250%, 1/15/30 – MBIA Insured    7/09 at 100.00    AA    20,069,202 
21,500     0.000%, 1/15/32 – MBIA Insured    No Opt. Call    AA    3,448,170 
12,525    San Jose Redevelopment Agency, California, Tax Allocation Bonds, Merged Area Redevelopment    8/10 at 101.00    AA (4)    13,444,961 
     Project, Series 2002, 5.000%, 8/01/20 (Pre-refunded 8/01/10) – MBIA Insured             
19,595    San Jose Redevelopment Agency, California, Tax Allocation Bonds, Merged Area Redevelopment    8/17 at 100.00    AA    13,530,348 
     Project, Series 2006C, 4.250%, 8/01/30 – MBIA Insured             
11,250    Santa Ana Financing Authority, California, Lease Revenue Bonds, Police Administration and    No Opt. Call    AA    13,060,688 
     Housing Facility, Series 1994A, 6.250%, 7/01/24 – MBIA Insured             
6,785    Santa Clara Valley Water District, California, Water Revenue Bonds, Series 2006A, 3.750%,    6/16 at 100.00    AAA    5,861,901 
     6/01/25 – FSA Insured             
5,000    Walnut Energy Center Authority, California, Electric Revenue Bonds, Turlock Irrigation    1/14 at 100.00    A1    4,586,800 
     District, Series 2004A, 5.000%, 1/01/34 – AMBAC Insured             

405,475    Total California            339,001,936 

    Colorado – 7.1% (4.5% of Total Investments)             
1,080    Arkansas River Power Authority, Colorado, Power Revenue Bonds, Series 2006, 5.250%, 10/01/40 –    10/16 at 100.00    BBB    868,504 
     SYNCORA GTY Insured             
1,900    Aspen, Colorado, Sales Tax Revenue Bonds, Parks and Open Space, Series 2005B, 5.250%,    11/15 at 100.00    AAA    1,982,384 
     11/01/24 – FSA Insured             
1,000    Colorado Department of Transportation, Certificates of Participation, Series 2004, 5.000%,    6/14 at 100.00    AA    1,016,660 
     6/15/25 – MBIA Insured             
4,950    Denver Convention Center Hotel Authority, Colorado, Senior Revenue Bonds, Convention Center    12/13 at 100.00    N/R (4)    5,658,395 
     Hotel, Series 2003A, 5.000%, 12/01/33 (Pre-refunded 12/01/13) – SYNCORA GTY Insured             
1,740    Douglas County School District RE1, Douglas and Elbert Counties, Colorado, General Obligation    12/14 at 100.00    Aa2    1,747,813 
     Bonds, Series 2005B, 5.000%, 12/15/28 – FSA Insured             
35,995    E-470 Public Highway Authority, Colorado, Senior Revenue Bonds, Series 1997B, 0.000%,    No Opt. Call    AA–    11,691,536 
     9/01/23 – MBIA Insured             
30,800    E-470 Public Highway Authority, Colorado, Senior Revenue Bonds, Series 2000A, 5.750%, 9/01/35    9/10 at 102.00    AAA    33,685,958 
     (Pre-refunded 9/01/10) – MBIA Insured             
11,800    E-470 Public Highway Authority, Colorado, Senior Revenue Bonds, Series 2000B, 0.000%, 9/01/15    9/10 at 74.80    Aaa    8,620,490 
     (Pre-refunded 9/01/10) – MBIA Insured             
10,000    E-470 Public Highway Authority, Colorado, Toll Revenue Bonds, Series 2004A, 0.000%, 9/01/27 –    No Opt. Call    AA–    2,201,900 
     MBIA Insured             
4,520    Jefferson County School District R1, Colorado, General Obligation Bonds, Series 2004,    12/14 at 100.00    AAA    4,623,598 
     5.000%, 12/15/24 – FSA Insured (UB)             
2,500    Summit County School District RE-1, Summit, Colorado, General Obligation Bonds, Series 2004B,    12/14 at 100.00    Aa3    2,577,875 
     5.000%, 12/01/24 – FGIC Insured             
1,000    University of Colorado, Enterprise System Revenue Bonds, Series 2005, 5.000%, 6/01/30 –    6/15 at 100.00    AA    994,740 
     FGIC Insured             

107,285    Total Colorado            75,669,853 

    District of Columbia – 1.1% (0.7% of Total Investments)             
    District of Columbia Water and Sewerage Authority, Subordinate Lien Public Utility Revenue             
    Bonds, Series 2003:             
5,000     5.125%, 10/01/24 – FGIC Insured    10/13 at 100.00    AA    5,081,550 
5,000     5.125%, 10/01/25 – FGIC Insured    10/13 at 100.00    AA    5,052,350 
2,670    Washington Convention Center Authority, District of Columbia, Senior Lien Dedicated Tax    10/16 at 100.00    AAA    1,882,243 
     Revenue Bonds, Series 2007, Residuals 1606, 11.765%, 10/01/30 – AMBAC Insured (IF)             

12,670    Total District of Columbia            12,016,143 

    Florida – 6.0% (3.8% of Total Investments)             
1,000    Hillsborough County School Board, Florida, Certificates of Participation, Master Lease    7/15 at 100.00    AA    955,160 
     Program, Series 2005A, 5.000%, 7/01/26 – MBIA Insured             
    Indian Trace Development District, Florida, Water Management Special Benefit Assessment Bonds,             
    Series 2005:             
645     5.000%, 5/01/25 – MBIA Insured    5/15 at 102.00    Baa1    553,358 
1,830     5.000%, 5/01/27 – MBIA Insured    5/15 at 102.00    Baa1    1,523,493 
4,425    Jacksonville Economic Development Commission, Florida, Healthcare Facilities Revenue Bonds,    11/12 at 100.00    AA    4,169,810 
     Mayo Clinic, Series 2001C, 5.500%, 11/15/36 – MBIA Insured             
1,505    Lee County, Florida, Transportation Facilities Revenue Bonds, Series 2004B, 5.000%, 10/01/21 –    10/14 at 100.00    A    1,569,730 
     AMBAC Insured             
2,000    Marco Island, Florida, Water Utility System Revenue Bonds, Series 2003, 5.000%, 10/01/27 –    10/13 at 100.00    AA    1,954,760 
     MBIA Insured             
2,150    Miami-Dade County, Florida, Aviation Revenue Bonds, Miami International Airport, Series 2002A,    10/12 at 100.00    AAA    1,747,456 
     5.125%, 10/01/35 – FSA Insured (Alternative Minimum Tax)             
35,920    Miami-Dade County, Florida, Aviation Revenue Bonds, Miami International Airport, Series 2002,    10/12 at 100.00    AA    29,284,856 
     5.375%, 10/01/32 – FGIC Insured (Alternative Minimum Tax)             
12,930    Miami-Dade County, Florida, Public Facilities Revenue Bonds, Jackson Health System, Series    12/15 at 100.00    AA    9,873,089 
     2005A, 5.000%, 6/01/32 – MBIA Insured             
5,320    Miami-Dade County, Florida, Public Facilities Revenue Bonds, Jackson Health System, Series    6/15 at 100.00    AA    4,497,528 
     2005B, 5.000%, 6/01/25 – MBIA Insured             
    Northern Palm Beach County Improvement District, Florida, Revenue Bonds, Water Control and             
    Improvement Development Unit 9B, Series 2005:             
1,290     5.000%, 8/01/23 – MBIA Insured    8/15 at 102.00    AA    1,298,875 
2,145     5.000%, 8/01/29 – MBIA Insured    8/15 at 102.00    AA    1,964,799 
2,320    Osceola County, Florida, Transportation Revenue Bonds, Osceola Parkway, Series 2004, 5.000%,    4/14 at 100.00    A3    2,288,123 
     4/01/23 – MBIA Insured             
2,225    Plantation, Florida, Non-Ad Valorem Revenue Refunding and Improvement Bonds, Series 2003,    8/13 at 100.00    Aa3    2,391,942 
     5.000%, 8/15/18 – FSA Insured             

75,705    Total Florida            64,072,979 

    Georgia – 1.1% (0.7% of Total Investments)             
1,000    Atlanta, Georgia, Water and Wastewater Revenue Bonds, Series 2004, 5.000%, 11/01/22 –    11/14 at 100.00    AAA    1,027,480 
     FSA Insured             
1,520    College Park Business and Industrial Development Authority, Georgia, Revenue Bonds, Public    9/14 at 102.00    AA    1,584,585 
     Safety Project, Series 2004, 5.250%, 9/01/23 – MBIA Insured             
    Fulton County Development Authority, Georgia, Revenue Bonds, Georgia Tech Molecular Science             
    Building, Series 2004:             
1,695     5.250%, 5/01/19 – MBIA Insured    5/14 at 100.00    AA    1,866,771 
1,135     5.250%, 5/01/20 – MBIA Insured    5/14 at 100.00    AA    1,226,776 
4,500     5.000%, 5/01/36 – MBIA Insured    5/14 at 100.00    AA    4,369,275 
1,250    Glynn-Brunswick Memorial Hospital Authority, Georgia, Revenue Bonds, Southeast Georgia Health    4/09 at 100.00    AA    1,251,200 
     Systems, Series 1996, 5.250%, 8/01/13 – MBIA Insured             

11,100    Total Georgia            11,326,087 

    Idaho – 0.3% (0.2% of Total Investments)             
170    Idaho Housing Agency, Single Family Mortgage Senior Bonds, Series 1994B-1, 6.750%, 7/01/22    No Opt. Call    Aa1    178,264 
135    Idaho Housing Agency, Single Family Mortgage Senior Bonds, Series 1994B-2, 6.900%, 7/01/26    No Opt. Call    Aa1    139,614 
     (Alternative Minimum Tax)             
235    Idaho Housing Agency, Single Family Mortgage Senior Bonds, Series 1995B, 6.600%, 7/01/27    7/09 at 100.00    Aaa    246,123 
     (Alternative Minimum Tax)             
    Idaho Housing and Finance Association, Grant and Revenue Anticipation Bonds, Federal Highway             
    Trust Funds, Series 2006:             
1,000     5.000%, 7/15/23 – MBIA Insured    7/16 at 100.00    Aa3    1,052,980 
1,065     5.000%, 7/15/24 – MBIA Insured    7/16 at 100.00    Aa3    1,109,293 

2,605    Total Idaho            2,726,274 

    Illinois – 5.7% (3.6% of Total Investments)             
1,050    Bedford Park, Illinois, General Obligation Bonds, Series 2004A, 5.250%, 12/15/20 – FSA Insured    12/14 at 100.00    AAA    1,144,731 
    Chicago, Illinois, Second Lien Passenger Facility Charge Revenue Refunding Bonds, O’Hare             
    International Airport, Series 2001E:             
4,615     5.500%, 1/01/17 – AMBAC Insured (Alternative Minimum Tax)    1/11 at 101.00    A1    4,665,534 
4,870     5.500%, 1/01/18 – AMBAC Insured (Alternative Minimum Tax)    1/11 at 101.00    A1    4,902,337 
7,200    Chicago, Illinois, Third Lien General Airport Revenue Bonds, O’Hare International Airport,    1/16 at 100.00    AA    7,119,000 
     Series 2005A, 5.250%, 1/01/24 – MBIA Insured             
10,000    Illinois Development Finance Authority, Revenue Bonds, Provena Health, Series 1998A, 5.500%,    5/09 at 100.50    AA    9,541,900 
     5/15/21 – MBIA Insured             
2,095    Illinois Educational Facilities Authority, Revenue Bonds, Robert Morris College, Series 2000,    6/09 at 100.00    Baa1    2,032,506 
     5.800%, 6/01/30 – MBIA Insured             
22,510    Illinois, General Obligation Bonds, Illinois FIRST Program, Series 2002, 5.125%, 2/01/27 –    2/12 at 100.00    AA    22,681,076 
     FGIC Insured             
    Schaumburg, Illinois, General Obligation Bonds, Series 2004B:             
4,260     5.000%, 12/01/22 – FGIC Insured    12/14 at 100.00    AA+    4,437,685 
2,365     5.000%, 12/01/23 – FGIC Insured    12/14 at 100.00    AA+    2,443,589 
4,000    Southwestern Illinois Development Authority, School Revenue Bonds, Triad School District 2,    No Opt. Call    AA    1,577,080 
     Madison County, Illinois, Series 2006, 0.000%, 10/01/25 – MBIA Insured             

62,965    Total Illinois            60,545,438 

    Indiana – 3.9% (2.4% of Total Investments)             
2,030    Decatur Township-Marion County Multi-School Building Corporation, Indiana, First Mortgage    7/13 at 100.00    AA+ (4)    2,340,204 
     Bonds, Series 2003, 5.000%, 7/15/20 (Pre-refunded 7/15/13) – FGIC Insured             
8,000    Indiana Municipal Power Agency, Power Supply Revenue Bonds, Series 2007A, 5.000%, 1/01/42 –    1/17 at 100.00    AA    7,021,920 
     MBIA Insured             
20,000    Indianapolis Local Public Improvement Bond Bank, Indiana, Series 1999E, 0.000%, 2/01/28 –    No Opt. Call    AA    6,873,800 
     AMBAC Insured             
3,250    Indianapolis Local Public Improvement Bond Bank, Indiana, Waterworks Project, Series 2002A,    7/12 at 100.00    AAA    3,652,968 
     5.250%, 7/01/33 (Pre-refunded 7/01/12) – MBIA Insured             
1,340    Monroe-Gregg Grade School Building Corporation, Morgan County, Indiana, First Mortgage Bonds,    1/14 at 100.00    AAA    1,553,556 
     Series 2004, 5.000%, 1/15/25 (Pre-refunded 1/15/14) – FSA Insured             
5,000    Noblesville Redevelopment Authority, Indiana, Economic Development Lease Rental Bonds, Exit 10    7/13 at 100.00    AA–    4,827,650 
     Project, Series 2003, 5.000%, 1/15/28 – AMBAC Insured             
10,000    Purdue University, Indiana, Student Fee Bonds, Series 2002O, 5.000%, 7/01/19 – MBIA Insured    1/12 at 100.00    Aa1    10,436,600 
3,705    Whitley County Middle School Building Corporation, Columbia City, Indiana, First Mortgage    7/13 at 100.00    AAA    4,271,161 
     Bonds, Series 2003, 5.000%, 7/15/16 (Pre-refunded 7/15/13) – FSA Insured             

53,325    Total Indiana            40,977,859 

    Kansas – 1.4% (0.9% of Total Investments)             
2,055    Kansas Turnpike Authority, Revenue Bonds, Series 2004A-2, 5.000%, 9/01/23 – FSA Insured    9/14 at 101.00    AAA    2,164,922 
    Neosho County Unified School District 413, Kansas, General Obligation Bonds, Series 2006:             
2,145     5.000%, 9/01/27 – FSA Insured    9/14 at 100.00    Aa3    2,200,577 
4,835     5.000%, 9/01/29 – FSA Insured    9/14 at 100.00    Aa3    4,914,826 
5,000    University of Kansas Hospital Authority, Health Facilities Revenue Bonds, KU Health System,    9/09 at 100.00    AAA    5,138,050 
     Series 1999A, 5.650%, 9/01/29 (Pre-refunded 9/01/09) – AMBAC Insured             

14,035    Total Kansas            14,418,375 

    Kentucky – 2.3% (1.5% of Total Investments)             
3,870    Kenton County School District Finance Corporation, Kentucky, School Building Revenue Bonds,    6/14 at 100.00    Aa3    3,931,301 
     Series 2004, 5.000%, 6/01/20 – MBIA Insured             
7,500    Kentucky Turnpike Authority, Economic Development Road Revenue Bonds, Revitalization Project,    7/16 at 100.00    AA+    7,669,950 
     Series 2006B, 5.000%, 7/01/25 – AMBAC Insured             
12,980    Louisville and Jefferson County Metropolitan Sewer District, Kentucky, Sewer and Drainage    11/11 at 101.00    AA    13,016,733 
     System Revenue Bonds, Series 2001A, 5.500%, 5/15/34 – MBIA Insured             

24,350    Total Kentucky            24,617,984 

    Louisiana – 5.9% (3.7% of Total Investments)             
5,000    DeSoto Parish, Louisiana, Pollution Control Revenue Refunding Bonds, Cleco Utility Group Inc.    9/09 at 102.00    A    4,631,750 
     Project, Series 1999, 5.875%, 9/01/29 – AMBAC Insured             
3,025    Lafayette City and Parish, Louisiana, Utilities Revenue Bonds, Series 2004, 5.250%, 11/01/22 –    11/14 at 100.00    AA    3,155,771 
     MBIA Insured             
4,545    Louisiana Public Facilities Authority, Revenue Bonds, Baton Rouge General Hospital, Series    7/14 at 100.00    AA    4,310,024 
     2004, 5.250%, 7/01/24 – MBIA Insured             
    Louisiana State, Gasoline and Fuels Tax Revenue Bonds, Series 2005A:             
2,400     5.000%, 5/01/25 – FGIC Insured    5/15 at 100.00    AA    2,432,856 
4,415     5.000%, 5/01/26 – FGIC Insured    5/15 at 100.00    AA    4,451,689 
5,000     5.000%, 5/01/27 – FGIC Insured    5/15 at 100.00    AA    5,015,600 
    Louisiana State, Gasoline and Fuels Tax Revenue Bonds, Series 2006:             
3,300     4.750%, 5/01/39 – FSA Insured (UB)    5/16 at 100.00    AAA    3,032,370 
35,725     4.500%, 5/01/41 – FGIC Insured (UB)    5/16 at 100.00    Aa3    30,528,085 
38    Louisiana State, Gasoline Tax Revenue Bonds, Series 2006, Residuals 660-1, 14.252%, 5/01/41 –    5/16 at 100.00    Aa3    16,028 
     FGIC Insured (IF)             
4,950    Orleans Levee District, Louisiana, Levee District General Obligation Bonds, Series 1986,    6/09 at 100.00    AAA    4,963,365 
     5.950%, 11/01/15 – FSA Insured             

68,398    Total Louisiana            62,537,538 

    Maine – 0.3% (0.2% of Total Investments)             
3,000    Maine Health and Higher Educational Facilities Authority, Revenue Bonds, Series 2003B, 5.000%,    7/13 at 100.00    AAA    3,010,500 
     7/01/28 – FSA Insured             

    Maryland – 0.3% (0.2% of Total Investments)             
5,345    Baltimore, Maryland, Senior Lien Convention Center Hotel Revenue Bonds, Series 2006A, 5.250%,    9/16 at 100.00    Baa3    3,554,425 
     9/01/28 – SYNCORA GTY Insured             

    Massachusetts – 5.8% (3.7% of Total Investments)             
22,500    Massachusetts Development Finance Authority, Revenue Bonds, WGBH Educational Foundation,    1/12 at 101.00    A (4)    25,358,850 
     Series 2002A, 5.375%, 1/01/42 (Pre-refunded 1/01/12) – AMBAC Insured             
11,000    Massachusetts School Building Authority, Dedicated Sales Tax Revenue Bonds, Series 2005A,    8/15 at 100.00    AAA    11,517,770 
     5.000%, 8/15/23 – FSA Insured (UB)             
7,255    Massachusetts Water Resources Authority, General Revenue Bonds, 4.500%, 8/01/46 –    2/17 at 100.00    AAA    6,155,868 
     FSA Insured (UB)             
15,000    Massachusetts, Special Obligation Dedicated Tax Revenue Bonds, Series 2004, 5.250%, 1/01/23    1/14 at 100.00    A (4)    17,088,000 
     (Pre-refunded 1/01/14) – FGIC Insured             
1,500    University of Massachusetts Building Authority, Senior Lien Project Revenue Bonds, Series    11/14 at 100.00    A+ (4)    1,796,115 
     2004-1, 5.375%, 11/01/20 (Pre-refunded 11/01/14) – AMBAC Insured             

57,255    Total Massachusetts            61,916,603 

    Michigan – 7.0% (4.4% of Total Investments)             
5,490    Detroit City School District, Wayne County, Michigan, Unlimited Tax School Building and Site    No Opt. Call    AAA    6,081,548 
     Improvement Bonds, Series 2001A, 6.000%, 5/01/29 – FSA Insured (UB)             
6,000    Detroit, Michigan, General Obligation Bonds, Series 2001A-1, 5.375%, 4/01/18 – MBIA Insured    10/11 at 100.00    AA    5,357,040 
7,420    Detroit, Michigan, Senior Lien Water Supply System Revenue Bonds, Series 1997A, 5.000%,    4/09 at 100.00    AA–    6,580,279 
     7/01/27 – MBIA Insured             
    Detroit, Michigan, Sewerage Disposal System Revenue Bonds, Series 1999A:             
15,825     5.750%, 7/01/26 (Pre-refunded 1/01/10) – FGIC Insured    1/10 at 101.00    Aaa    16,723,069 
20,000     5.875%, 7/01/27 (Pre-refunded 1/01/10) – FGIC Insured    1/10 at 101.00    Aaa    21,158,000 
1,085    Grand Rapids Community College, Kent County, Michigan, General Obligation Refunding Bonds,    5/13 at 100.00    AA    1,178,484 
     Series 2003, 5.250%, 5/01/20 – AMBAC Insured             
6,850    Wayne County, Michigan, Airport Revenue Bonds, Detroit Metropolitan Wayne County Airport,    12/09 at 100.50    AA    6,912,335 
     Series 1998A, 5.375%, 12/01/15 – MBIA Insured (Alternative Minimum Tax)             
10,000    Wayne County, Michigan, Limited Tax General Obligation Airport Hotel Revenue Bonds, Detroit    12/11 at 101.00    AA    10,092,500 
     Metropolitan Wayne County Airport, Series 2001A, 5.250%, 12/01/25 – MBIA Insured             

72,670    Total Michigan            74,083,255 

    Minnesota – 2.3% (1.5% of Total Investments)             
5,000    City of Minneapolis, Minnesota, Health Care System Revenue Bonds, Series 2008B,    11/18 at 100.00    AAA    5,300,300 
     6.500%, 11/15/38 – AGC Insured             
4,000    Northern Municipal Power Agency, Minnesota, Electric System Revenue Bonds, Refunding Series    No Opt. Call    AAA    4,378,600 
     2009A, 5.000%, 1/01/15 (WI/DD, Settling 2/11/09) – AGC Insured             
13,020    Saint Paul Housing and Redevelopment Authority, Minnesota, Multifamily Housing Revenue Bonds,    12/11 at 102.00    Aaa    15,177,935 
     Marian Center Project, Series 2001A, 6.450%, 6/20/43 (Pre-refunded 12/20/11)             

22,020    Total Minnesota            24,856,835 

    Nebraska – 2.8% (1.7% of Total Investments)             
27,125    Lincoln, Nebraska, Electric System Revenue Bonds, Series 2007A, 4.500%, 9/01/37 –    9/17 at 100.00    AA    23,462,040 
     FGIC Insured (UB)             
5,000    Municipal Energy Agency of Nebraska, Power Supply System Revenue and Refunding Bonds, Series    4/19 at 100.00    AAA    5,032,700 
     2009A, 5.375%, 4/01/39 – BHAC Insured             
1,000    Nebraska Public Power District, General Revenue Bonds, Series 2005A, 5.000%, 1/01/25 –    1/15 at 100.00    AAA    1,010,160 
     FSA Insured             

33,125    Total Nebraska            29,504,900 

    Nevada – 7.9% (4.9% of Total Investments)             
8,475    Clark County, Nevada, General Obligation Bank Bonds, Southern Nevada Water Authority Loan,    12/12 at 100.00    AA+    7,885,310 
     Series 2002, 5.000%, 6/01/32 – MBIA Insured             
3,630    Clark County, Nevada, General Obligation Bank Bonds, Southern Nevada Water Authority Loan,    12/12 at 100.00    Aa1 (4)    4,127,274 
     Series 2002, 5.000%, 6/01/32 (Pre-refunded 12/01/12) – MBIA Insured             
7,370    Clark County, Nevada, Subordinate Lien Airport Revenue Bonds, Series 2004A-2, 5.125%,    7/14 at 100.00    AA    7,253,186 
     7/01/25 – FGIC Insured             
    Director of Nevada State Department of Business and Industry, Revenue Bonds, Las Vegas             
    Monorail Project, First Tier, Series 2000:             
15,000     5.625%, 1/01/34 – AMBAC Insured    1/10 at 102.00    A    6,483,300 
13,000     5.375%, 1/01/40 – AMBAC Insured    1/10 at 100.00    A    5,620,290 
14,985    Reno, Nevada, Capital Improvement Revenue Bonds, Series 2002, 5.375%, 6/01/32 – FGIC Insured    6/12 at 100.00    Baa1    12,292,046 
25,300    Reno, Nevada, Capital Improvement Revenue Bonds, Series 2002, 5.375%, 6/01/32 (Pre-refunded    6/12 at 100.00    Baa1 (4)    28,579,386 
     6/01/12) – FGIC Insured             
10,000    Reno, Nevada, Senior Lien Sales and Room Tax Revenue Bonds, Reno Transportation Rail Access    6/12 at 100.00    A (4)    11,229,000 
     Corridor Project, Series 2002, 5.125%, 6/01/27 (Pre-refunded 6/01/12) – AMBAC Insured             

97,760    Total Nevada            83,469,792 

    New Jersey – 2.5% (1.6% of Total Investments)             
    Essex County Improvement Authority, New Jersey, Guaranteed Revenue Bonds, Project             
    Consolidation, Series 2004:             
2,000     5.125%, 10/01/21 – MBIA Insured    10/14 at 100.00    A1    2,086,720 
2,250     5.125%, 10/01/22 – MBIA Insured    10/14 at 100.00    A1    2,322,383 
    New Jersey Economic Development Authority, Revenue Bonds, Motor Vehicle Surcharge,             
    Series 2004A:             
3,850     5.000%, 7/01/22 – MBIA Insured    7/14 at 100.00    AA    3,922,996 
3,850     5.000%, 7/01/23 – MBIA Insured    7/14 at 100.00    AA    3,889,886 
8,250    New Jersey Turnpike Authority, Revenue Bonds, Series 2003A, 5.000%, 1/01/19 – FGIC Insured    7/13 at 100.00    AA    8,681,640 
    New Jersey Turnpike Authority, Revenue Bonds, Series 2005A:             
3,320     5.000%, 1/01/21 – FSA Insured (UB)    1/15 at 100.00    AAA    3,538,390 
2,000     5.000%, 1/01/23 – FSA Insured (UB)    7/13 at 100.00    AAA    2,036,400 

25,520    Total New Jersey            26,478,415 

    New Mexico – 0.3% (0.2% of Total Investments)             
3,660    San Juan County, New Mexico, Subordinate Gross Receipts Tax Revenue Bonds, Series 2005,    6/15 at 100.00    AA    3,663,733 
     5.000%, 6/15/25 – MBIA Insured             

    New York – 7.0% (4.4% of Total Investments)             
1,880    Dormitory Authority of the State of New York, FHA-Insured Mortgage Revenue Bonds, Montefiore    2/15 at 100.00    AA–    1,825,818 
     Hospital, Series 2004, 5.000%, 8/01/23 – FGIC Insured             
3,335    Dormitory Authority of the State of New York, State Personal Income Tax Revenue Bonds, Series    3/15 at 100.00    AAA    3,418,942 
     2005F, 5.000%, 3/15/24 – AMBAC Insured             
3,820    Hudson Yards Infrastructure Corporation, New York, Revenue Bonds, Series 2006A, 4.500%,    2/17 at 100.00    AA    2,829,398 
     2/15/47 – MBIA Insured             
12,500    Long Island Power Authority, New York, Electric System General Revenue Bonds, Series 2006A,    6/16 at 100.00    AA    12,207,250 
     5.000%, 12/01/25 – FGIC Insured             
6,900    Long Island Power Authority, New York, Electric System Revenue Bonds, Series 2006F, 4.250%,    11/16 at 100.00    AA    5,381,448 
     5/01/33 – MBIA Insured             
    Metropolitan Transportation Authority, New York, State Service Contract Refunding Bonds,             
    Series 2002A:             
1,500     5.000%, 7/01/21 – FGIC Insured    7/12 at 100.00    AA    1,536,360 
5,000     5.000%, 7/01/25 – FGIC Insured    7/12 at 100.00    AA    5,002,900 
2,615    New York City Industrial Development Agency, New York, Revenue Bonds, Yankee Stadium Project    3/19 at 100.00    AAA    2,757,308 
     Pilot, Series 2009A, 7.000%, 3/01/49 (WI/DD, Settling 2/05/09) – AGC Insured             
5,000    New York City, New York, General Obligation Bonds, Fiscal Series 2005F-1, 5.000%, 9/01/21 –    9/15 at 100.00    AA    5,146,700 
     AMBAC Insured             
10,000    New York City, New York, General Obligation Bonds, Fiscal Series 2005M, 5.000%, 4/01/26 –    4/15 at 100.00    AA    9,751,800 
     FGIC Insured             
5,000    New York State Thruway Authority, General Revenue Bonds, Series 2005F, 5.000%, 1/01/26 –    1/15 at 100.00    A+    4,965,950 
     AMBAC Insured             
    New York State Urban Development Corporation, State Personal Income Tax Revenue Bonds,             
    Series 2004A-1:             
1,000     5.000%, 3/15/23 – FGIC Insured    3/14 at 100.00    AAA    1,028,320 
5,000     5.000%, 3/15/25 – FGIC Insured    3/14 at 100.00    AAA    5,071,450 
3,650    New York State Urban Development Corporation, State Personal Income Tax Revenue Bonds, Series    3/15 at 100.00    AAA    3,720,737 
     2005B, 5.000%, 3/15/25 – FSA Insured (UB)             
10,000    Triborough Bridge and Tunnel Authority, New York, Subordinate Lien General Purpose Revenue    11/12 at 100.00    AA    9,701,400 
     Refunding Bonds, Series 2002E, 5.000%, 11/15/32 – MBIA Insured             

77,200    Total New York            74,345,781 

    North Carolina – 1.6% (1.0% of Total Investments)             
    Mooresville, North Carolina, Enterprise System Revenue Bonds, Series 2004:             
2,115     5.000%, 5/01/22 – FGIC Insured    5/14 at 100.00    AA    2,175,806 
2,575     5.000%, 5/01/26 – FGIC Insured    5/14 at 100.00    AA    2,548,400 
5,000    North Carolina Municipal Power Agency 1, Catawba Electric Revenue Bonds, Series 2003A, 5.250%,    1/13 at 100.00    AAA    5,467,150 
     1/01/16 – FSA Insured             
    Raleigh Durham Airport Authority, North Carolina, Airport Revenue Bonds, Series 2005A:             
3,205     5.000%, 5/01/23 – AMBAC Insured    5/15 at 100.00    Aa3    3,266,760 
3,295     5.000%, 5/01/24 – AMBAC Insured    5/15 at 100.00    Aa3    3,322,909 

16,190    Total North Carolina            16,781,025 

    North Dakota – 0.6% (0.4% of Total Investments)             
    Grand Forks, North Dakota, Sales Tax Revenue Bonds, Alerus Project, Series 2005A:             
2,195     5.000%, 12/15/22 – MBIA Insured    12/15 at 100.00    A1    2,277,576 
1,355     5.000%, 12/15/23 – MBIA Insured    12/15 at 100.00    A1    1,385,040 
3,000     5.000%, 12/15/24 – MBIA Insured    12/15 at 100.00    A1    3,038,310 

6,550    Total North Dakota            6,700,926 

    Ohio – 3.1% (1.9% of Total Investments)             
2,650    Cleveland State University, Ohio, General Receipts Bonds, Series 2004, 5.250%, 6/01/24 –    6/14 at 100.00    AA–    2,714,130 
     FGIC Insured             
2,000    Columbus City School District, Franklin County, Ohio, General Obligation Bonds, Series 2004,    12/14 at 100.00    AAA    2,384,980 
     5.250%, 12/01/25 (Pre-refunded 12/01/14) – FSA Insured             
2,385    Columbus, Ohio, Tax Increment Financing Bonds, Easton Project, Series 2004A, 5.000%,    6/14 at 100.00    A    2,344,407 
     12/01/22 – AMBAC Insured             
2,205    Hamilton City School District, Ohio, General Obligation Bonds, Series 2005, 5.000%, 12/01/24 –    6/15 at 100.00    Baa1    2,223,919 
     MBIA Insured             
6,535    Hamilton County, Ohio, Sales Tax Revenue Bonds, Tender Option Bond Trust 2706, 7.443%,    12/16 at 100.00    A2    2,831,223 
     12/01/32 – AMBAC Insured (IF)             
20,100    Lucas County, Ohio, Hospital Revenue Bonds, ProMedica Healthcare Obligated Group, Series 1999,    11/09 at 101.00    A    16,874,754 
     5.375%, 11/15/39 – AMBAC Insured             
3,000    Ross Local School District, Butler County, Ohio, General Obligation Bonds, Series 2003,    12/13 at 100.00    Aa3 (4)    3,488,130 
     5.000%, 12/01/28 (Pre-refunded 12/01/13) – FSA Insured             

38,875    Total Ohio            32,861,543 

    Oklahoma – 3.2% (2.0% of Total Investments)             
3,500    Oklahoma Capitol Improvement Authority, State Facilities Revenue Bonds, Series 2005F, 5.000%,    7/15 at 100.00    AA    3,578,890 
     7/01/24 – AMBAC Insured             
2,920    Oklahoma Housing Finance Agency, GNMA Collateralized Single Family Mortgage Revenue Bonds,    No Opt. Call    AAA    3,166,302 
     Series 1987A, 7.997%, 8/01/18 (Alternative Minimum Tax)             
21,000    Oklahoma Municipal Power Authority, Power Supply System Revenue Bonds, Series 2007, 4.500%,    1/17 at 100.00    AA    16,836,120 
     1/01/47 – FGIC Insured             
5,245    Oklahoma State Industries Authority, Revenue Bonds, Oklahoma Medical Research Foundation,    2/11 at 100.00    A1    5,348,222 
     Series 2001, 5.250%, 2/01/21 – AMBAC Insured             
4,880    University of Oklahoma, Student Housing Revenue Bonds, Series 2004, 5.000%, 7/01/22 –    7/14 at 100.00    A1    5,024,399 
     AMBAC Insured             

37,545    Total Oklahoma            33,953,933 

    Oregon – 0.3% (0.2% of Total Investments)             
2,535    Oregon Department of Administrative Services, Certificates of Participation, Series 2005A,    5/15 at 100.00    AAA    2,577,943 
     5.000%, 5/01/25 – FSA Insured             
1,030    Oregon Housing and Community Services Department, Single Family Mortgage Revenue Bonds,    7/09 at 100.00    Aa2    1,030,505 
     Series 1995A, 6.450%, 7/01/26 (Alternative Minimum Tax)             

3,565    Total Oregon            3,608,448 

    Pennsylvania – 3.4% (2.1% of Total Investments)             
7,925    Commonwealth Financing Authority, Pennsylvania, State Appropriation Lease Bonds, Series 2006A,    6/16 at 100.00    AAA    8,073,594 
     5.000%, 6/01/26 – FSA Insured (UB)             
1,800    Pennsylvania Higher Educational Facilities Authority, Revenue Bonds, Drexel University, Series    5/15 at 100.00    AA    1,737,288 
     2005A, 5.000%, 5/01/28 – MBIA Insured             
11,740    Pennsylvania Public School Building Authority, Lease Revenue Bonds, School District of    12/16 at 100.00    AAA    9,973,717 
     Philadelphia, Series 2006B, 4.500%, 6/01/32 – FSA Insured (UB)             
2,625    Pennsylvania Turnpike Commission, Turnpike Revenue Bonds, Series 2006A, 5.000%, 12/01/26 –    6/16 at 100.00    Aa3    2,624,816 
     AMBAC Insured             
6,335    Radnor Township School District, Delaware County, Pennsylvania, General Obligation Bonds,    8/15 at 100.00    Aa3    6,366,422 
     Series 2005B, 5.000%, 2/15/30 – FSA Insured             
    Reading School District, Berts County, Pennsylvania, General Obligation Bonds, Series 2005:             
3,285     5.000%, 1/15/22 – FSA Insured (UB)    1/16 at 100.00    AAA    3,455,853 
3,450     5.000%, 1/15/23 – FSA Insured (UB)    1/16 at 100.00    AAA    3,589,449 

37,160    Total Pennsylvania            35,821,139 

    Puerto Rico – 0.9% (0.6% of Total Investments)             
2,500    Puerto Rico Electric Power Authority, Power Revenue Bonds, Series 2005RR, 5.000%, 7/01/30    7/15 at 100.00    AAA    2,983,750 
     (Pre-refunded 7/01/15) – SYNCORA GTY Insured             
2,000    Puerto Rico Highway and Transportation Authority, Highway Revenue Bonds, Series 2003G, 5.250%,    7/13 at 100.00    BBB+    1,874,620 
     7/01/19 – FGIC Insured             
1,550    Puerto Rico Municipal Finance Agency, Series 2005C, 5.250%, 8/01/21 – CIFG Insured    No Opt. Call    BBB–    1,429,534 
36,000    Puerto Rico Sales Tax Financing Corporation, Sales Tax Revenue Bonds, Series 2007A, 0.000%,    No Opt. Call    AA–    3,586,320 
     8/01/42 – FGIC Insured             

42,050    Total Puerto Rico            9,874,224 

    Rhode Island – 2.4% (1.5% of Total Investments)             
2,195    Providence Housing Development Corporation, Rhode Island, FHA-Insured Section 8 Assisted    7/09 at 100.00    AA    2,197,810 
     Mortgage Revenue Refunding Bonds, Barbara Jordan Apartments, Series 1994A, 6.750%,             
     7/01/25 – MBIA Insured             
20,475    Rhode Island Depositors Economic Protection Corporation, Special Obligation Refunding Bonds,    2/11 at 100.00    AA (4)    22,128,971 
     Series 1993B, 5.250%, 8/01/21 (Pre-refunded 2/01/11) – MBIA Insured             
1,405    Rhode Island Health & Educational Building Corporation, Higher Education Auxiliary Enterprise    9/14 at 100.00    A2    1,454,723 
     Revenue Bonds, Series 2004A, 5.500%, 9/15/24 – AMBAC Insured             

24,075    Total Rhode Island            25,781,504 

    South Carolina – 6.7% (4.2% of Total Investments)             
14,650    Anderson County School District 5, South Carolina, General Obligation Bonds, Series 2008,    2/18 at 100.00    AAA    14,817,010 
     Trust 1181, 8.484%, 2/01/38 – FSA Insured (IF)             
10,000    Beaufort County, South Carolina, Tax Increment Bonds, New River Redevelopment Project, Series    12/12 at 100.00    AA    9,776,300 
     2002, 5.000%, 6/01/27 – MBIA Insured             
    Medical University Hospital Authority, South Carolina, FHA-Insured Mortgage Revenue Bonds,             
    Series 2004A:             
2,000     5.250%, 8/15/22 – MBIA Insured    8/14 at 100.00    AA    1,994,000 
2,105     5.250%, 8/15/23 – MBIA Insured    8/14 at 100.00    AA    2,069,468 
4,855    Piedmont Municipal Power Agency, South Carolina, Electric Revenue Bonds, Series 1988A, 0.000%,    No Opt. Call    Aaa    4,227,249 
     1/01/13 – AMBAC Insured (ETM)             
715    Piedmont Municipal Power Agency, South Carolina, Electric Revenue Bonds, Series 1988A, 0.000%,    7/09 at 76.63    Aa3 (4)    545,895 
     1/01/13 (Pre-refunded 7/01/09) – AMBAC Insured             
7,955    Piedmont Municipal Power Agency, South Carolina, Electric Revenue Bonds, Series 1988A, 0.000%,    No Opt. Call    A    6,659,528 
     1/01/13 – AMBAC Insured             
8,000    South Carolina JOBS Economic Development Authority, Industrial Revenue Bonds, South Carolina    11/12 at 100.00    A    7,989,840 
     Electric and Gas Company, Series 2002A, 5.200%, 11/01/27 – AMBAC Insured             
10,000    South Carolina JOBS Economic Development Authority, Industrial Revenue Bonds, South Carolina    11/12 at 100.00    A    8,236,500 
     Electric and Gas Company, Series 2002B, 5.450%, 11/01/32 – AMBAC Insured (Alternative             
     Minimum Tax)             
17,500    South Carolina Transportation Infrastructure Bank, Revenue Bonds, Series 2007A, 4.500%,    10/16 at 100.00    A1    14,480,375 
     10/01/34 – SYNCORA GTY Insured             

77,780    Total South Carolina            70,796,165 

    Tennessee – 0.6% (0.4% of Total Investments)             
6,455    Memphis-Shelby County Airport Authority, Tennessee, Airport Revenue Bonds, Series 2001A,    3/11 at 100.00    AAA    6,526,392 
     5.500%, 3/01/18 – FSA Insured (Alternative Minimum Tax)             

    Texas – 15.2% (9.5% of Total Investments)             
22,650    Brazos River Authority, Texas, Revenue Refunding Bonds, Houston Industries Inc., Series 1998C,    5/09 at 101.00    AA    19,200,179 
     5.125%, 5/01/19 – AMBAC Insured             
521    Capital Area Housing Finance Corporation, Texas, FNMA Backed Single Family Mortgage Revenue    4/12 at 106.00    Aaa    544,060 
     Refunding Bonds, Series 2002A-2, 6.300%, 4/01/35 – AMBAC Insured (Alternative Minimum Tax)             
12,500    Dallas-Ft. Worth International Airport, Texas, Joint Revenue Bonds, Series 2000A, 6.125%,    11/09 at 100.00    AA    11,727,500 
     11/01/35 – FGIC Insured (Alternative Minimum Tax)             
    Harris County, Texas, Toll Road Senior Lien Revenue Bonds, Series 1989:             
9,000     0.000%, 8/15/18 (Pre-refunded 8/15/09) – AMBAC Insured    8/09 at 53.84    Aaa    4,821,750 
39,000     0.000%, 8/15/19 (Pre-refunded 8/15/09) – AMBAC Insured    8/09 at 50.26    Aaa    19,504,680 
7,280     0.000%, 8/15/20 (Pre-refunded 8/15/09) – AMBAC Insured    8/09 at 46.91    Aaa    3,398,814 
5,085     0.000%, 8/15/21 (Pre-refunded 8/15/09) – AMBAC Insured    8/09 at 43.80    Aaa    2,216,145 
25,000    Harris County-Houston Sports Authority, Texas, Junior Lien Revenue Refunding Bonds, Series    11/11 at 100.00    AA    18,461,750 
     2001B, 5.250%, 11/15/40 – MBIA Insured             
4,671    Houston Housing Finance Corporation, Texas, GNMA Collateralized Mortgage Multifamily Housing    9/11 at 105.00    Aaa    4,684,546 
     Revenue Bonds, RRG Apartments Project, Series 2001, 6.350%, 3/20/42             
    Houston, Texas, First Lien Combined Utility System Revenue Bonds, Series 2004A:             
4,000     5.250%, 5/15/24 – FGIC Insured    5/14 at 100.00    AA    4,027,200 
5,000     5.250%, 5/15/25 – MBIA Insured    5/14 at 100.00    AA    5,095,700 
17,500    Houston, Texas, Hotel Occupancy Tax and Special Revenue Bonds, Convention and Entertainment    9/11 at 100.00    A    17,005,100 
     Project, Series 2001B, 5.250%, 9/01/33 – AMBAC Insured             
23,865    Jefferson County Health Facilities Development Corporation, Texas, FHA-Insured Mortgage    8/11 at 100.00    A    20,333,935 
     Revenue Bonds, Baptist Hospital of Southeast Texas, Series 2001, 5.500%, 8/15/41 –             
     AMBAC Insured             
140    Lower Colorado River Authority, Texas, Revenue Refunding and Improvement Bonds, Series 2001A,    5/11 at 100.00    AA (4)    152,337 
     5.000%, 5/15/21 (Pre-refunded 5/15/11) – MBIA Insured             
8,065    Lower Colorado River Authority, Texas, Revenue Refunding and Improvement Bonds, Series 2001A,    5/11 at 100.00    AA    8,263,480 
     5.000%, 5/15/21 – MBIA Insured             
    Port of Houston Authority, Harris County, Texas, General Obligation Port Improvement Bonds,             
    Series 2001B:             
3,205     5.500%, 10/01/18 – FGIC Insured (Alternative Minimum Tax)    10/11 at 100.00    AAA    3,230,416 
3,375     5.500%, 10/01/19 – FGIC Insured (Alternative Minimum Tax)    10/11 at 100.00    AAA    3,380,265 
7,205    San Antonio, Texas, Airport System Improvement Revenue Bonds, Series 2001, 5.375%, 7/01/15 –    7/11 at 101.00    AA    7,362,357 
     FGIC Insured (Alternative Minimum Tax)             
7,550    Waco Health Facilities Development Corporation, Texas, Hillcrest Health System Project, FHA    8/16 at 100.00    AA    5,844,455 
     Insured Mortgage Revenue Bonds, Series 2006A, 5.000%, 8/01/31 – MBIA Insured             
1,840    Ysleta Independent School District Public Facility Corporation, Texas, Lease Revenue Refunding    11/09 at 100.00    A+    1,869,348 
     Bonds, Series 2001, 5.375%, 11/15/24 – AMBAC Insured             

207,452    Total Texas            161,124,017 

    Utah – 1.6% (1.0% of Total Investments)             
2,000    Clearfield City, Utah, Sales Tax Revenue Bonds, Series 2003, 5.000%, 7/01/28 (Pre-refunded    7/13 at 100.00    AA– (4)    2,293,140 
     7/01/13) – FGIC Insured             
15,000    Utah Transit Authority, Sales Tax Revenue Bonds, Series 2008A, 5.000%, 6/15/32 – FSA Insured    6/18 at 100.00    AAA    14,836,050 

17,000    Total Utah            17,129,190 

    Virginia – 1.5% (0.9% of Total Investments)             
1,035    Loudoun County Industrial Development Authority, Virginia, Lease Revenue Bonds, Public Safety    6/14 at 100.00    AAA    1,128,243 
     Facilities, Series 2003A, 5.250%, 12/15/20 – FSA Insured             
4,840    Metropolitan Washington D.C. Airports Authority, Airport System Revenue Bonds, Series 2001A,    10/11 at 101.00    AA    4,889,513 
     5.500%, 10/01/19 – MBIA Insured (Alternative Minimum Tax)             
10,000    Virginia Housing Development Authority, Commonwealth Mortgage Bonds, Series 2001H-1, 5.375%,    7/11 at 100.00    AAA    9,935,600 
     7/01/36 – MBIA Insured             

15,875    Total Virginia            15,953,356 

    Washington – 2.6% (1.6% of Total Investments)             
2,500    Grant County Public Utility District 2, Washington, Revenue Bonds, Wanapum Hydroelectric    1/15 at 100.00    AA    2,387,575 
     Development, Series 2005A, 5.000%, 1/01/29 – FGIC Insured             
3,500    King County School District 401, Highline, Washington, General Obligation Bonds, Series 2004,    12/14 at 100.00    AA+    3,618,685 
     5.000%, 10/01/24 – FGIC Insured             
3,195    Kitsap County, Washington, Limited Tax General Obligation Bonds, Series 2000, 5.500%, 7/01/25    7/10 at 100.00    AA– (4)    3,410,982 
     (Pre-refunded 7/01/10) – AMBAC Insured             
4,250    Snohomish County Public Utility District 1, Washington, Generation System Revenue Bonds,    7/09 at 100.00    Aaa    5,515,608 
     Series 1989, 6.650%, 1/01/16 – FGIC Insured (ETM)             
    Tacoma, Washington, Solid Waste Utility Revenue Refunding Bonds, Series 2006:             
3,890     5.000%, 12/01/24 – SYNCORA GTY Insured    12/16 at 100.00    AA    3,919,836 
4,085     5.000%, 12/01/25 – SYNCORA GTY Insured    12/16 at 100.00    AA    4,075,523 
4,290     5.000%, 12/01/26 – SYNCORA GTY Insured    12/16 at 100.00    AA    4,225,049 

25,710    Total Washington            27,153,258 

    Wisconsin – 2.6% (1.6% of Total Investments)             
15,000    Wisconsin Health and Educational Facilities Authority, Revenue Bonds, Marshfield Clinic,    2/09 at 100.00    AA    12,848,700 
     Series 1997, 5.750%, 2/15/27 – MBIA Insured             
290    Wisconsin, General Obligation Bonds, Series 2004-3, 5.250%, 5/01/20 – FGIC Insured    5/14 at 100.00    Aa3    312,988 
2,600    Wisconsin, General Obligation Bonds, Series 2004-3, 5.250%, 5/01/20 (Pre-refunded 5/01/14) –    5/14 at 100.00    Aa3 (4)    3,064,594 
     FGIC Insured             
10,945    Wisconsin, General Obligation Bonds, Series 2004-4, 5.000%, 5/01/20 – MBIA Insured    5/14 at 100.00    AA    11,688,057 

28,835    Total Wisconsin            27,914,339 

$    1,931,700    Total Investments (cost $1,745,496,288) – 159.2%            1,689,525,746 


    Floating Rate Obligations – (8.6)%            (90,833,333)

    Other Assets Less Liabilities – 6.9%            72,975,334 

    Auction Rate Preferred Shares, at Liquidation Value – (57.5)% (5)            (610,400,000)

    Net Assets Applicable to Common Shares – 100%          $  1,061,267,747 



    At least 80% of the Fund’s net assets (including net assets attributable to Auction Rate Preferred shares) 
    are invested in municipal securities that are covered by insurance or backed by an escrow or trust account 
    containing sufficient U.S. Government or U.S. Government agency securities or U.S. Treasury-issued State 
    and Local Government Series securities to ensure the timely payment of principal and interest. 
(1)    All percentages shown in the Portfolio of Investments are based on net assets applicable to Common 
    shares unless otherwise noted. 
(2)    Optional Call Provisions: Dates (month and year) and prices of the earliest optional call or redemption. 
    There may be other call provisions at varying prices at later dates. Certain mortgage-backed securities 
    may be subject to periodic principal paydowns. 
(3)    Ratings: Using the higher of Standard & Poor's Group ("Standard & Poor's") or Moody's Investor Service, 
    Inc. ("Moody's") rating. Ratings below BBB by Standard & Poor's or Baa by Moody's are considered to be 
    below investment grade. 
    The Portfolio of Investments may reflect the ratings on certain bonds insured by ACA, AGC, AMBAC, CIFG, 
    FGIC, FSA, MBIA, RAAI and SYNCORA as of January 31, 2009. Subsequent to January 31, 2009, and 
    during the period this Portfolio of Investments was prepared, there may have been reductions to the 
    ratings of certain bonds resulting from changes to the ratings of the underlying insurers both during the 
    period and after period end. Such reductions would likely reduce the effective rating of many of the bonds 
    insured by that insurer or insurers presented at period end. 
(4)    Backed by an escrow or trust containing sufficient U.S. Government or U.S. Government agency securities 
    which ensure the timely payment of principal and interest. Such investments are normally considered to 
    be equivalent to AAA rated securities. 
(5)    Auction Rate Preferred Shares, at Liquidation Value as a percentage of Total Investments is 36.1%. 
N/R    Not rated. 
(ETM)    Escrowed to maturity. 
WI/DD    Purchased on a when-issued or delayed delivery basis. 
(IF)    Inverse floating rate investment. 
(UB)    Underlying bond of an inverse floating rate trust reflected as a financing transaction pursuant to the 
    provisions of SFAS No. 140. 

Fair Value Measurements

During the current fiscal period, the Fund adopted the provisions of Statement of Financial Accounting Standards No. 157 (SFAS No.157) “Fair Value Measurements.” SFAS No. 157 defines fair value, establishes a framework for measuring fair value in generally accepted accounting principles, and expands disclosure about fair value measurements. In determining the value of the Fund's investments various inputs are used. These inputs are summarized in the three broad levels listed below:

Level 1 – Quoted prices in active markets for identical securities. 
Level 2 – Other significant observable inputs (including quoted prices for similar securities, interest rates, 
              prepayment speeds, credit risk, etc.). 
Level 3 – Significant unobservable inputs (including management's assumptions in determining the fair 
              value of investments). 

The inputs or methodology used for valuing securities are not an indication of the risk associated with investing in those securities.

The following is a summary of the Fund's fair value measurements as of January 31, 2009:

    Level 1    Level 2           Level 3    Total 

Investments    $ —             $1,689,525,746     $ —            $1,689,525,746 


Income Tax Information

The following information is presented on an income tax basis. Differences between amounts for financial statement and federal income tax purposes are primarily due to timing differences in recognizing taxable market discount, timing differences in recognizing certain gains and losses on investment transactions and the treatment of investments in inverse floating rate transactions subject to SFAS No. 140. To the extent that differences arise that are permanent in nature, such amounts are reclassified within the capital accounts on the Statement of Assets and Liabilities presented in the annual report, based on their federal tax basis treatment; temporary differences do not require reclassification. Temporary and permanent differences do not impact the net asset value of the Fund.

At January 31, 2009, the cost of investments was $1,653,830,031.

Gross unrealized appreciation and gross unrealized depreciation of investments at January 31, 2009, were as follows:


Gross unrealized:     
  Appreciation    $  69,364,970 
  Depreciation    (124,497,178)

Net unrealized appreciation (depreciation) of investments    $ (55,132,208)



Item 2. Controls and Procedures.

  1. The registrant's principal executive and principal financial officers, or persons performing similar functions, have concluded that the registrant's disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the "1940 Act") (17 CFR 270.30a-3(c))) are effective, as of a date within 90 days of the filing date of this report that includes the disclosure required by this paragraph, based on their evaluation of the controls and procedures required by Rule 30a-3(b) under the 1940 Act (17 CFR 270.30a-3(b)) and Rule 13a-15(b) or 15d-15(b) under the Securities Exchange Act of 1934 (17 CFR 240.13a-15(b) or 240.15d-15(b)).
  2. There were no changes in the registrant's internal control over financial reporting (as defined in Rule 30a-3(d) under the 1940 Act (17 CFR 270.30a-3(d)) that occurred during the registrant's last fiscal quarter that have materially affected, or are reasonably likely to materially affect, the registrant's internal control over financial reporting.

Item 3. Exhibits.

File as exhibits as part of this Form a separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the 1940 Act (17 CFR 270.30a-2(a)), exactly as set forth below: See EX-99 CERT attached hereto.


SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

(Registrant)         Nuveen Insured Municipal Opportunity Fund, Inc.         

By (Signature and Title)          /s/ Kevin J. McCarthy                    
                                                  Kevin J. McCarthy
                                                  Vice President and Secretary

Date         April 1, 2009        

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By (Signature and Title)         /s/ Gifford R. Zimmerman                    
                                                 Gifford R. Zimmerman
                                                 Chief Administrative Officer (principal executive officer) 

Date         April 1, 2009        

By (Signature and Title)         /s/ Stephen D. Foy                              
                                                 Stephen D. Foy
                                                 Vice President and Controller (principal financial officer) 

Date        April 1, 2009