The volume of the music played will decrease down to zero, until the phone is silenced. This erratic behavior happens when I plugged in the Nokia earpiece shipped with the phone although I can't determine when exactly it would happen (sporadic). I have found this to happen on my 920 and 1020. When I change the earpiece to a normal headphone, the problems did not show up. And no, I left it on my bed openly without anything touching the volume rocker. You can literally see the volume go down from the displayed numbers. At times, when I tried to push the volume up again, the volume counters my action by decreasing itself. Nokia really needs to look at this. Have emailed them.