Although by now most of the bugs have been worked out of the XP SP2 updates and there's certainly no reason to uninstall it if your computer is functioning fine with it, there does appear to be a lingering problem for some people with their IEEE1394 firewire connections not working correctly.

If you're one of those who's having this problem, check out this recently issued Microsoft fix (KB885222):
http://www.microsoft.com/downloads/details.aspx?FamilyID=5c076e4c-aec8-434d-9849-e668a50e6e81&displaylang=en&Hash=XKC4S9