UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13G

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                                (AMENDMENT 4)*


                           Infinity Property & Casualty
   --------------------------------------------------------------------------
                                (Name of Issuer)

                                 COMMON STOCK
   --------------------------------------------------------------------------
                         (Title of Class of Securities)

                                   45665Q103
   --------------------------------------------------------------------------
                                 (CUSIP Number)

                                  08/31/2008
   --------------------------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)



Check the  appropriate box to designate the rule pursuant to which this Schedule
is filed:

         [X]     Rule 13d-1(b)
         [ ]     Rule 13d-1(c)
         [ ]     Rule 13d-1(d)

*The  remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for any  subsequent  amendment  containing  information  which  would  alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).


CUSIP No. 45665Q103

     1.   Names of Reporting Persons.
          I.R.S. Identification Nos. of above persons (entities only).

          Dimensional Fund Advisors LP (Tax ID: 30-0447847)

     2.   Check the Appropriate Box if a Member of a Group (See Instructions)

          (a)
          (b)  X

     3.   SEC Use Only

     4.   Citizenship or Place of Organization

          Delaware Limited Partnership


                   5.    Sole Voting Power
Number of Shares         1,538,025  **see Note 1**
Beneficially
Owned by           6.    Shared Voting Power
Each Reporting           None
Person With
                   7.    Sole Dispositive Power
                         1,538,025  **see Note 1**

                   8.    Shared Dispositive Power
                         None

     9.   Aggregate Amount Beneficially Owned by Each Reporting Person

          1,538,025  **see Note 1**

     10.  Check if the Aggregate  Amount in Row (9) Excludes Certain Shares (See
          Instructions)

          N/A

     11.  Percent of Class Represented by Amount in Row (9)

          10.05%

     12.  Type of Reporting Person (See Instructions)

          IA



Item 1.

         (a)      Name of Issuer

                  Infinity Property & Casualty


         (b)      Address of Issuer's Principal Executive Offices

                  3700 Colonnade Parkway
                  Birmingham, AL 35243

Item 2.

         (a)      Name of Person Filing

                  Dimensional Fund Advisors LP


         (b)      Address of Principal Business Office, or if none, Residence

                  1299 Ocean Avenue, Santa Monica, CA 90401


         (c)      Citizenship

                  Delaware Limited Partnership


         (d)      Title of Class of Securities

                  Common Stock


         (e)      CUSIP Number

                  45665Q103


Item 3.  If  this  statement  is  filed  pursuant   to Sec. 240.13d-1(b)  or
     240.13d-2(b) or (c), check whether the person filing is a:


     (a)  [ ]  Broker or dealer registered under section 15 of the Act
               (15 U.S.C. 78o).

     (b)  [ ]  Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

     (c)  [ ]  Insurance  company as defined in section  3(a)(19) of the Act (15
               U.S.C. 78c).

     (d)  [ ]  Investment company  registered  under section 8 of the Investment
               Company Act of 1940 (15 U.S.C. 80a-8).

     (e)  [X]  An  investment  adviser  in  accordance  with Sec. 240.13d-1(b)
               (1)(ii)(E);

     (f)  [ ]  An  employee  benefit  plan or endowment fund in accordance  with
               Sec. 240.13d-1(b)(1)(ii)(F);

     (g)  [ ]  A parent holding  company  or  control person in accordance  with
               Sec. 240.13d-1(b)(1)(ii)(G);

     (h)  [ ]  A savings associations  as defined in Section 3(b) of the Federal
               Deposit Insurance Act (12 U.S.C. 1813);

     (i)  [ ]  A church  plan  that  is  excluded  from  the  definition  of  an
               investment  company  under  section  3(c)(14)  of  the Investment
               Company Act of 1940 (15 U.S.C. 80a-3);

     (j)  [ ]  Group, in accordance with Sec. 240.13d-1(b)(1)(ii)(J).

Item 4.  Ownership

Provide the following  information regarding the aggregate number and percentage
of the class of securities of the issuer identified in Item 1.

     (a)  Amount beneficially owned:      1,538,025  **see Note 1**

     (b)  Percent of class:               10.05%

     (c)  Number of shares as to which the person has:

          (i)   Sole power to vote or to direct the vote

                1,538,025  **see Note 1**

          (ii)  Shared power to vote or to direct the vote

                None

          (iii) Sole power to dispose or to direct the disposition of

                1,538,025  **see Note 1**

          (iv)  Shared power to dispose or to direct the disposition of

                None

**  Note  1  **   Dimensional  Fund  Advisors  LP  (formerly,  Dimensional  Fund
Advisors   Inc.)  ("Dimensional"),   an  investment  advisor   registered  under
Section 203  of the   Investment  Advisors  Act of  1940, furnishes   investment
advice to four investment   companies  registered under the  Investment  Company
Act of  1940,  and  serves as   investment  manager  to certain other commingled
group  trusts and  separate accounts.  These investment  companies, trusts   and
accounts  are  the  "Funds."   In its  role as   investment  advisor or manager,
Dimensional   possesses  voting  and/or  investment  power  over  the securities
of the Issuer described in this schedule that are owned by the Funds, and may be
deemed to  be the   beneficial  owner  of the  shares of  the Issuer held by the
Funds. However, all securities reported in this schedule are owned by the Funds.
Dimensional   disclaims   beneficial   ownership   of   such   securities.    In
addition, the filing of this Schedule 13G shall not be construed as an admission
that the reporting  person or any of its affiliates is the  beneficial  owner of
any securities  covered by this Schedule 13G for any other purposes than Section
13(d) of the Securities Exchange Act of 1934.


Item 5.  Ownership of Five Percent or Less of a Class

If this  statement  is being filed to report the fact that as of the date hereof
the  reporting  person has ceased to be the  beneficial  owner of more than five
percent of the class of securities, check the following [ ].

N/A

Item 6.  Ownership of More Than Five Percent on Behalf of Another Person

The Funds  described in Note 1 above  have the right to receive or the power to
direct the receipt of  dividends  from,  or the  proceeds  from the sale of, the
securities held in their  respective  accounts.  To the knowledge of Dimensional
Fund Advisors  LP, the interest of any  one such Fund does not exceed 5%  of the
class  of  securities.  Dimensional  Fund  Advisors LP  disclaims  beneficial
ownership of all such securities.

Item 7.  Identification  and Classification of the Subsidiary Which Acquired the
         Security  Being  Reported  on By  the Parent Holding Company or Control
         Person.

N/A

Item 8.  Identification and Classification of Members of the Group

N/A


Item 9.  Notice of Dissolution of Group

N/A


Item 10. Certification

     By signing  below I certify  that,  to the best of my knowledge and belief,
     the securities referred to above were acquired and are held in the ordinary
     course of business  and were not  acquired and are not held for the purpose
     of or with the effect of changing or influencing  the control of the issuer
     of the securities and were not acquired and are not held in connection with
     or as a participant in any transaction having that purpose or effect.




                                    SIGNATURE

After  reasonable  inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.


                                      September 9, 2008
                                      ---------------------------
                                      Date

                                      /s/ Christopher Crossan
                                      ---------------------------
                                      Signature

                                      Chief Compliance Officer
                                      ---------------------------
                                      Name/Title