Dylanmusic,
Have you ever synced it in the past? Did you rename, move or delete your Application Support folder, Library folder or SyncServices folder? If so that could have caused the issue as discussed in this article:
http://docs.info.apple.com/article.html?artnum=301920
Also sometimes software will sync with it without letting the user know. Do you have Entourage installed? If so, in its preferences turn off the sync services options. After making that change in Entourage, or if you don't have Entourage: Open iSync, go to Preferences and click on Reset Sync History.
Make the corrections to your address book and they should not get changed again.
If they get changed again, back up your Address Book entries, or export them to vCard before we troubleshoot further.
Hope this helps,
Nathan C.