I put fresh batteries (Energizer 357) into my OM-2, everything worked fine, red light stayed red.. Shot a roll of film, turned camera off, then next day went to shoot another roll, and the mirror locked-up and the check light blinked.. I don't know if this is because I had my camera bag it was in on the floor and something to do with it being semi-cold? Or if off really isn't off? For those of you with OM-2/3/4 how long does your batteries generally last?