We're running Outlook 2003 and Exchange 2003 on the back end. One of
our users, random items from his Sent Items folder disappear. Just poof
from Outlook, never to return to it. But through OWA, we can see that
the items are still in the Send Items folder.

Very strange. Cleanly uninstalled the whole Office suite, re-installed
without any problems. Reconfigured Outlook to our usual specs. Problem
is still there, but no other problems.

Anyone have any suggestions?

TIA