pnfadd.dll and infheaa.dll

pnfadd.dll and infheaa.dll
I have a client with a WinXP Home system. I have scanned with updated Adaware, Spybot and checked with Hijack This and and running WinPatrol and he still gets popups from Winpatrol every minute or so when IE is open about the listed dll files attempting to change the home page, etc. He has NAV 2003 and it is current and updated and does not find anything in a scan also. We have the latedt MS updates in stalled. I deleted the infheaa.dll in safe mode and it stopped for a while. Now the pnfadd.dl is starting the same thing. I cannot find any reference to these files anywhere. Any Ideas??