“Phantom” Word window in Outlook 2003

I have one user recently upgraded to Outlook 2003 (from XP) who is getting a blank word window (gray) every time he opens Outlook. Sometimes it can be closed, sometimes not.
I have seen this before but do not know what I can do to stop it.

BTW, the user is the President of our company so I am trying to fix this asap… 🙂