Please help!!! After successfully completing my M3 transplant into my 318is coupe and running it for six months I have encountered my first challenge... Quite a major one at that too. In the last four days I have managed to have two keys lose their communication with the car which has obviously resulted in the car not starting. I'm happy enough to buy new keys but I find this odd, these keys are only six months old. One packed up, but the spare was ok. Now that one has done exactly the same as the first. Is it coincidental or is their a problem elsewhere? 

I'd appreciate all help on this one

Many thanks

Steve