this is a problem that happens every once in a while. it seems to do it more when it is cold out. I bought the optima yellow top battery about 2 months ago becuase i was having some battery problems. so i'll start my car up and it will start up just fine. i will put my car in drive and it will go just like usual, but if i put it in reverse, the car shuts off. it also will shut off sometimes if i hit the brakes hard or hit a big bump in the road. ive talked to a few people about this and no one can come up with an explanation. i wanted to see if anyone here could have some ideas on what the problem is before i shelll the money out to get it looked out. it doesnt do it all the time either.