Cannot sync with Active Sync error

Group,
I have a Win 2K laptop, a Samsung i700 Phone/PC. I have had both well over a
year. Just recently I have become unable to sync via ActiveSync. I
repeatedly get the error. "ActiveSync cannot be completed
successfully....... Please restart active sync or consult the online help
utility." This of course was no help. I have reset the PPC, I have restarted
the computer, I have restarted the PPC then the computer, I have uninstalled
ActiveSync, I have deleted the partnership then uninstalled and reinstalled
ActiveSync, Re-starting in between for good measure. Any help from those
MVP's?
ActiveSync finds the PPC and starts the sync, but fails just before starting
to exchange files. A new partnership is created. I can connect as a guest,
and explore the device.