When the backup battery goes dead you loose the ID number.
http://www.pacificsites.com/~alanjudd/922.htm
If you have lost your receiver ID number you will need a new main board.
Check the receiver number in the status screen. If it matches the UA number on the back sticker you are ok, if not the only solution is replacing the main board. ATSelectronics.com still had some boards when I last checked. But when they run out were all screwed.
Motorola didn't make any provisions for renewing the ID number.
That really sucks motorola ;-(

I have a dsr 410 receiver,the id looks normal but a guy at skyvision told me the id number was not in they data base & told me the receiver cannot receiver a hit,how can i tell if this id # has a problem