[scandata]

Same thing happened to me and also to another member here, although we both also slammed on our brakes at the same time, so one of those two (if not both) caused the radio to mute. I think that's a security feature; if you have to use your horn and/or brakes, you don't need the distraction of music playing, so it mutes. I can't see the use in disconnecting a phone call though unless that's unavoidable because of the way it's wired.