SP2 does a lot of bad things and that's why I didn't install it again after I cleaned down last. I used to have a SCSI scanner that worked fine using pre-SP2 version. However, after SP2 was installed, it lost my scanner even though the hardware properties said it was "working correctly". It didn't show up on the list of SCSI devices. My paint packages etc that used the scanner told me there were no twain devices that they could use. Re-installed XP without the patch and the scanner works fine again.
This is not the only hardware that gets lost after SP2 is installed. I've heard of DVD writers, internal modems and even hard disks that suddenly don't exist any more after the patch.