I don't know about that, but XP refuses to let my mouse work the way I intend it to. For some reason if both users are logged in it will not let me use my side buttons on my intellimouse optical. It also has flaky issues with the buttons, since I swap the left/right clicks and my roommate doesn't.. Sometimes I have to go in, change something, hit apply again to get it to work.. but that still doesn't fix the side buttons.
Intellipoint software 3.2 or 4 has the same issue.