Syncing contacts with Exchange only partially successful

[lessismore]

My Droid X synced my contacts to my Exchange 2003 server the first time with no problems. It also synced calendar and email perfectly and continues to do so. Since the initial contact sync from Exchange to the phone however, no changes made to contacts on Exchange or to the contacts on the phone have been synced to the other. I do not use Google contacts and have it turned off. Again; syncing email and calendar with Exchange continues to work great.