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                                                                    Exhibit 24.2


                        POWER OF ATTORNEY AND SIGNATURES

     KNOW ALL PERSONS BY THESE PRESENTS THAT each person whose signature appears
below hereby constitutes and appoints Raymond J. Spencer and William F. Weissman
as his true and lawful attorneys-in-fact and agents, with full power of
substitution and resubstitution, for him and in his name, place and stead, in
any and all capacities, to sign any and all amendments (including post-effective
amendments) to the registration statement on form S-1, and any registration
statements filed pursuant to Rule 462(b) under the Securities Act of 1933, as
amended, and to file the same, with all exhibits thereto, and all documents in
connection therewith, with the Securities and Exchange Commission, granting unto
said attorneys-in-fact and agents, full power and authority to do and perform
each and every act and thing requisite and necessary to be done in and about the
premises, as fully to all intents and purposes as he might or could do in
person, hereby ratifying, and confirming all that said attorneys-in-fact and
agents, or their substitutes, may lawfully do or cause to be done by virtue
hereof.

     Pursuant to the requirements of the Securities Act of 1933, as amended,
this registration statement has been signed by the following persons in the
capacities and on the dates indicated.

<Table>
<Caption>
          Signature                     Title                                   Date
          ---------                     -----                                   ----
                                                                     
                                   Chairman of the Board and Chief
- ---------------------------------  Executive Officer (principal
     Raymond J. Spencer            executive officer)


                                   Vice President and Chief Financial
- ---------------------------------  Officer (principal accounting and
     William F. Weissman           financial officer)

     /s/ Donald R. Caldwell        Director                                October 28, 2004
- ---------------------------------
     Donald R. Caldwell

                                   Director
- ---------------------------------
     Cyprian D'Souza

                                   Director
- ---------------------------------
     Mark L. Gordon
</Table>

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<Table>
                                                                     
                                   Director
- ---------------------------------
     Kenneth M. Harvey

                                   Director
- ---------------------------------
     B. Douglas Morriss

                                   Director
- ---------------------------------
     Michael E. Mikolajczyk
</Table>