Same thing happened to mine last night after defrosting it - driving me nuts!!! Did a couple of things, sprayed it with WD40 and poured hot water in the bottom of the freezer while moving that door stop thing in the bottom around. The beeping got quieter and eventually stopped. Can only guess that either the hot water melted a build up of ice that was making it beep or WD40 is a magic potion made from the souls of electricians.
Andy, September 2007