Just out of curiousity,,, did you happen to FDISK and Format C when you did you XP install??
I have had to rebuild a number of systems where XP was simply run as an upgrade over an existing Win98 install.. sounds like it shouldnt be a problem right?
Well,, seems more like WRONG!,, the Latency Drivers in XP seem to install improperly on an upgrade,, this can cause numerous glitches in Hardware,and Apps,,
Plus,, did you happen to see if there is a BIOS update for your MOBO,, some manufacturers require that you run an update in order to SUPPORT XP,,,
My inclination is to backup files,, research and download all updates for your hardware,, FDISK, FORMAT and reinstall a CLEAN copy of XP,,
You may have better luck in the long run,, and not be "turned off" by the move to XP,,,
cheers, and good luck!