deleted items checkbox unchecking itself

I have a user running Win2000 with Outlook 2003. He checks the "delete mail
upon exiting" checkbox. When he exits Outlook it works fine, and mail gets
deleted.

When he logs back onto the computer the next time, he fires up Outlook, and
the checkbox is no longer checked. Does Outlook write something to a registry
key to tell if the checkbox is checked or not? If so, does anyone know which
key it is? This is happening to two of the users in my company

Thanks in advance,
Joe