When I use the Outlook 2003 client, I inevitably get the above message at
some point. I cannot click OK to get rid of the message window, either. I
have to use the End Task function to close the Outlook 2003 entirely.

My client has never worked correctly, so I've tended to use Outlook Web
Access instead, but I'd really like to have access to all of the features of
the full Outlook 2003. Ideas?