Since the user is running Access 2002 on Windows XP, it's quite likely they're also using Word 2002.

I suspect the issue is that the Access data default's to today's date when blank. If today's date is never valid, you could use an IF field to suppress it:
{IF{MERGEFIELD Report_Date \@ "dd/MM/yyyy"} <> {DATE \@ "dd/MM/yyyy"} {MERGEFIELD Report_Date \@ "dd/MM/yyyy"}}

Note: The field brace pairs (ie '{ }') for the above example are created in the body of the document via Ctrl-F9 (Cmd-F9 on a Mac) - you can't simply type them or copy & paste them from this message.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]