Cannot Close Word 2007 by depressing the X button

I have an end user who cannot close Word 2007 (any document) when he
depresses the X in Word. All the other office apps close fine with the X
button and it is just Word. I've done the following...

1. Uninstalled Office 2007 and reinstalled
2. Checked for any add-ins (there were none)
3. Deleted the normal.dot.
4. Unsuccessfully tried doing a systems restore to a previous date

I haven't found any answers except changing account profiles. I'd prefer
not to do this because of the virtual machine on his PC (it would just be a
pain to recreate).

The end user swears nothing has changed on his PC. Any suggestions would
be great.