BMW will tell you that you are "not using a certified or approved handset so it must be your phone". Have you updated the phone and the car to the latest software version? I know that there are lots of problems recently with Bluetooth and BMW/Mini. There was a recent release that solved a lot of what you're talking about. Download it from the BMW portal to a USB stick and install in the car, also update your phone to latest and greatest. Then cross your fingers!