Did you guys ever get a definite answer on this. My 2010 sport has started doing this same thing. Oddly, at the same time, other things appear to be happening. The volume control is unresponsive initially, it takes it about 10 seconds to recognize I moved the volume up or down. Also, the "Sound" button that controls the treble, bass, fade, etc is not responding at all. I have done a master reset, did not appear to help anything. My software appears to be up to date as well.