Symantec has already posted on their website that WinFax pro has issues with SP 2.

Also note that PlanetPress/Objectiflune does not support Service 2 for windows XP.

http://service1.symantec.com/SUPPORT/faxprod.nsf/docid/2004071911425704?Open&src=w

That is a link to symantec's site. Please note that their "work around" posted here has not been tested here and we do not know if that workaround will fix the issues with PlanetPress fax.