I've had my new 2001 X5 for about a week now. My radio mutes itself sometimes but I do not know why. It is mute when I first start the car but not every time. The radio has the station displayed but there is no sound. I have the prewired connections for the phone but do not have the phone installed. If I turn the radio off and then on again it works fine. I know it mutes on incoming calls when the phone is installed because I previously had a 540 with a BMW phone. Anyone know what the deal is? Thanks.