SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C.  20549

                                 SCHEDULE 13G
                                (Rule 13d-102)


             INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
           TO RULES 13d-1(b)(c), AND (d) AND AMENDMENTS THERETO FILED
                           PURSUANT TO RULE 13d-2(b)


                               (Amendment No. 4)*


                        Packaging Corporation of America
             -----------------------------------------------------
                                (Name of Issuer)

                                  common stock
             -----------------------------------------------------
                         (Title of Class of Securities)

                                    695156109
             -----------------------------------------------------
                                 (CUSIP Number)


                               December 31, 2006
             -----------------------------------------------------
            (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-(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).

                                Page 1 of 9 Pages




CUSIP No. 695156109           Schedule 13G             Page 2 of 9 Pages


________________________________________________________________________________
1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Iridian Asset Management LLC

________________________________________________________________________________
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [X]

________________________________________________________________________________
3.   SEC USE ONLY



________________________________________________________________________________
4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     Delaware

________________________________________________________________________________
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES           N/A
               _________________________________________________________________
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY          N/A
               _________________________________________________________________
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING         N/A
               _________________________________________________________________
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH            N/A
________________________________________________________________________________
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     N/A

________________________________________________________________________________
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [_]

________________________________________________________________________________
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

     N/A

________________________________________________________________________________
12.  TYPE OF REPORTING PERSON*

     IA

________________________________________________________________________________
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!





CUSIP No. 695156109          Schedule 13G             Page 3 of 9 Pages


________________________________________________________________________________
1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     The Governor and Company of the Bank of Ireland

________________________________________________________________________________
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [X]

________________________________________________________________________________
3.   SEC USE ONLY



________________________________________________________________________________
4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     Republic of Ireland

________________________________________________________________________________
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES           N/A
               _________________________________________________________________
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY          N/A
               _________________________________________________________________
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING         N/A
               _________________________________________________________________
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH            N/A
________________________________________________________________________________
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     N/A

________________________________________________________________________________
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [_]

________________________________________________________________________________
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

     N/A

________________________________________________________________________________
12.  TYPE OF REPORTING PERSON*

     CO

________________________________________________________________________________
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!



CUSIP No. 695156109          Schedule 13G             Page 4 of 9 Pages


________________________________________________________________________________
1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     IBI Interfunding

________________________________________________________________________________
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [X]

________________________________________________________________________________
3.   SEC USE ONLY



________________________________________________________________________________
4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     Republic of Ireland

________________________________________________________________________________
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES           N/A
               _________________________________________________________________
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY          N/A
               _________________________________________________________________
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING         N/A
               _________________________________________________________________
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH            N/A
________________________________________________________________________________
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     N/A

________________________________________________________________________________
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [_]

________________________________________________________________________________
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

     N/A

________________________________________________________________________________
12.  TYPE OF REPORTING PERSON*

     CO

________________________________________________________________________________
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!




CUSIP No. 695156109           Schedule 13G             Page 5 of 9 Pages


________________________________________________________________________________
1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     BancIreland/First Financial, Inc.

________________________________________________________________________________
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [X]

________________________________________________________________________________
3.   SEC USE ONLY



________________________________________________________________________________
4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     New Hampshire

________________________________________________________________________________
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES           N/A
               _________________________________________________________________
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY          N/A
               _________________________________________________________________
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING         N/A
               _________________________________________________________________
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH            N/A
________________________________________________________________________________
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     N/A

________________________________________________________________________________
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [_]

________________________________________________________________________________
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

     N/A

________________________________________________________________________________
12.  TYPE OF REPORTING PERSON*

     CO

________________________________________________________________________________
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!




CUSIP No. 695156109           Schedule 13G             Page 6 of 9 Pages


________________________________________________________________________________
1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     BIAM (US) Inc.

________________________________________________________________________________
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [X]

________________________________________________________________________________
3.   SEC USE ONLY



________________________________________________________________________________
4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     Delaware

________________________________________________________________________________
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES           N/A
               _________________________________________________________________
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY          N/A
               _________________________________________________________________
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING         N/A
               _________________________________________________________________
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH            N/A
________________________________________________________________________________
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     N/A

________________________________________________________________________________
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [_]

________________________________________________________________________________
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

     N/A

________________________________________________________________________________
12.  TYPE OF REPORTING PERSON*

     CO

________________________________________________________________________________
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!



CUSIP No. 695156109             SCHEDULE 13G              Page 7 of 9 Pages

This Amendment  amends in its entirety the Schedule 13G previously filed for the
month ended December 31, 2005.

________________________________________________________________________________
Item 1(a).  Name of Issuer:

            Packaging Corporation of America

________________________________________________________________________________
Item 1(b).  Address of Issuer's Principal Executive Offices:

            1900 West Field Court
            Lake Forest, Illinois 60045
________________________________________________________________________________
Item 2.

(a)  Name of Person Filing.

This  Statement is being filed by and on behalf of Iridian Asset  Management LLC
("Iridian"),  The  Governor  and  Company of the Bank of  Ireland  (the "Bank of
Ireland"),   BIAM  Holdings  ("Holdings"),   BancIreland  (US)  Holdings,   Inc.
("BancIreland"), and BIAM (US) Inc. (collectively, the "Reporting Persons").


(b) Address of Principal Business Office:

The principal  business address of Iridian is 276 Post Road West,  Westport,  CT
06880-4704.

The principal  business  address of Bank of Ireland and Holdings is Head Office,
Lower Baggot Street, Dublin 2, Ireland.

The principal business address of BancIreland and BIAM (US) Inc. is Liberty Park
#15, 282 Route 101, Amherst, NH 03110.

(c)  Citizenship or Place of  Organization:

Iridian is a limited liability company. Bank of Ireland and Holdings are Ireland
corporations.  BancIreland is a New Hampshire  corporation.  BIAM (US) Inc. is a
Delaware corporation.

d) Title of Class of Securities:

This  Statement  relates  to the  shares of common  stock,  $.01 par  value,  of
Packaging Corporation of America.

(e)  CUSIP Number: The CUSIP number is 695156109.



CUSIP No. 695156109            SCHEDULE 13G              Page 8 of 9 Pages

_______________________________________________________________________________
Item 3. If This  Statement is Filed  Pursuant to Rule  13d-1(b),  or 13d-2(b) or
(c), Check Whether the Person Filing is a:

     (a)  [_]  Broker or dealer registered under Section 15 of the Exchange Act.

     (b)  [_]  Bank as defined in Section 3(a)(6) of the Exchange Act.

     (c)  [_]  Insurance  company as defined in Section 3(a)(19) of the Exchange
               Act.

     (d)  [_]  Investment  company  registered under Section 8 of the Investment
               Company Act.

     (e)  [X]  An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);

     (f)  [_]  An employee  benefit plan or endowment  fund in  accordance  with
               Rule 13d-1(b)(1)(ii)(F);

     (g)  [X]  A parent  holding  company or control  person in accordance  with
               Rule 13d-1(b)(1)(ii)(G);

     (h)  [_]  A savings  association  as defined in Section 3(b) of the Federal
               Deposit Insurance Act;

     (i)  [_]  A church  plan that is  excluded  from the  definition  of an
               investment  company  under  Section  3(c)(14)  of the  Investment
               Company Act;

     (j)  [_]  Group, in accordance with Rule 13d-1(b)(1)(ii)(J).


If this statement is filed pursuant to Rule 13d-1(c), check this box. [_]

_______________________________________________________________________________
Item 4.     Ownership.

Not Applicable.

________________________________________________________________________________
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: X


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

Not Applicable.

________________________________________________________________________________
Item 7.  Identification and Classification of the Subsidiary Which Acquired the
         Security Being Reported on by the Parent Holding Company.

Not Applicable.

________________________________________________________________________________
Item 8.  Identification and Classification of Members of the Group.

Not Applicable

________________________________________________________________________________
Item 9.  Notice of Dissolution of Group.

Not Applicable.

________________________________________________________________________________
Item 10.  Certifications.

By  signing  below the  undersigned  certifies  that,  to the best of its or his
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 and do not have 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 such purpose or
effect.



CUSIP No. 695156109             SCHEDULE 13-G              Page 9 of 9 Pages


                                   SIGNATURE.


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

Date: February 5, 2007


                              IRIDIAN ASSET MANAGEMENT LLC

                              By: /s/    Jeffrey M. Elliott
                                   ----------------------------------
                                       Jeffrey M. Elliott
                                       Executive Vice President


                              THE GOVERNOR AND COMPANY OF THE BANK OF IRELAND

                             By:   /s/   John Clifford
                                   ----------------------------------
                                        John Clifford
                                        Group Secretary


                              BIAM HOLDINGS

                             By:   /s/   Sean O'Dwyer
                                   ----------------------------------
                                        Sean O'Dwyer
                                        Director


                              BANCIRELAND (US) HOLDINGS, INC.

                              By:  /s/   Diane Morrison
                                    ----------------------------------
                                        Diane Morrison
                                        Director

                              BIAM (US) INC.

                              By:  /s/   Diane Morrison
                                    ----------------------------------
                                        Diane Morrison
                                        Director

                             JOINT FILING AGREEMENT


This JOINT FILING  AGREEMENT is made and entered into by and among Iridian Asset
Management  LLC,  The  Governor  and  Company  of  the  Bank  of  Ireland,   IBI
Interfunding, BancIreland/First Financial, Inc., and BIAM (US) Inc.

The parties to this  Agreement  hereby agree to prepare  jointly and file timely
(or otherwise  deliver as appropriate)  all filings on Schedule 13D and Schedule
13G (the  "Filings")  required to be filed by them  pursunat to Section 13(d) or
13(g) under the  Securities  Exchange Act of 1934,  as amended,  with respect to
their respective ownership of any securities of Packaging Corporation of America
that are  requireed to be reportd on any Filings.  Each party to this  Agreement
further  agrees and covenants to the other parties that it will fully  cooperate
with such  other  parties  in the  preparation  and  timely  filing  (and  other
delivery) of all such Filings.

Date: February 5, 2007



                              IRIDIAN ASSET MANAGEMENT LLC

                              By: /s/    Jeffrey M. Elliott
                                   ----------------------------------
                                       Jeffrey M. Elliott
                                       Executive Vice President


                              THE GOVERNOR AND COMPANY OF THE BANK OF IRELAND

                             By:   /s/   John Clifford
                                   ----------------------------------
                                        John Clifford
                                        Group Secretary


                              BIAM HOLDINGS

                             By:   /s/   Sean O'Dwyer
                                   ----------------------------------
                                        Sean O'Dwyer
                                        Director


                              BANCIRELAND (US) HOLDINGS, INC.

                              By:  /s/   Diane Morrison
                                    ----------------------------------
                                        Diane Morrison
                                        Director

                              BIAM (US) INC.

                              By:  /s/   Diane Morrison
                                    ----------------------------------
                                        Diane Morrison
                                        Director