Has anyone heard of Outlook 2003 removing attachments upon reading the msg?

I have a user who is receiving word attachments from a particular sender. He opens the message, then opens the attachment and leaves it open for a couple of minutes. When he goes back to the email, the attachment is gone. I’ve forwarded the message to myself and the attachment does not show up. I close outlook and reopen and the attachment is not there anymore. Any ideas??