Outlook 2002 DistLists no longer lists

I’m running Outlook 2002 under XP Home (SP2). I just noticed that all of my distribution lists have been somehow changed to no longer appear as distribution lists. They now show up as a single (empty) contact.

Any clues how this happened, or more importantly how to zap it back?

I don’t remember how many users were in each, so it’ll be very hard to re-create…