I have a client who has an IBM notebook that has Windows Vista Business and
Office 2007 Professional. He uses Outlook to connect to a SBS server at
their office using RPC over HTTP. This has been working fine for months.

Earlier this week he complained that he was no longer receiving email but
could send. Upon further investigation it appears that his Inbox is no
longer syncing between the server mailbox and .ost file. If I look at the
properties of the inbox and folder size, it will show that the server data
and local data do not match. If I disable Cached Exchange Mode, everything
works normally.

Next, I deleted his .ost file and had it recreate. Same problem. I then
deleted his email profile and recreated. Same problem. I have verified that
this is not an view or filter issue but I am at the end of my rope.

Any suggestions would be greatly appreciated.