I don't know if this is the case with Excel 2002, but I was working for a U.S. based subsidiary of a U.K company in advance of Y2k and I remember Excel getting its default sequencing of dates (regardless of the formatting option which determines how they will display), from the Windows setup. Go to your Control Panel and select Regional Options and select the Date tab and make sure your Short Date follows your desired dd/mm/yyyy. If information is getting entered to this spreadsheet from a user form and thus from a different computer, I think you could have a problem if their regional options are not in sync with yours. Just a thought.
TD