on the 3000, when you change the batteries, take out all of the old ones, WAIT 20 SECONDS then put in the new ones. Use quality brand new batteries. All orignal programing wiil be retained.

On the 3100 I have never had one dump its memory, I had had several lock up and contiously transmit which causes the batteries to go dead, but putting in new batteries restores the orignal programming.
I have had on 3 or 4 3100's, when the batteries totally die or the cutomer keeps using it after the screen goes to the clock reset page, the remote is totally dead even after new batteries were put in. The fix is to leave the batteries out for an hour or so, then put in new one and the remote will work again,

I know that doesnt make sense but it works.

cb1