Hm... maybe you could try this one:
In device manager (right click my computer > properties > Hardware tab >
Device manager) remove all the CD drives (delete them) and restart.
Was SP2 slipstreamed on your XP Pro? SP2, when is it installed normally can
be such a problem.... (I'm telling you this from my personal experience). If
this doesn't work try reinstalling with SP2 integraded installation of XP or
you can wait because the patch WILL be released...