Ok, running XP was getting the "iTunes was unable to load dataclass information from Sync Services. Reconnect or try again later." error message. I did two things to get it to work now, not sure if either one was the reason, but hey, it works.
1. On iTunes, go up to Edit, then to preferences. All the way on the right is the Syncing option. Click the "disable automatic syncing for iPhones and iPods", hit OK.
2. Restart computer.