When I am playing MP3s on an SD card while in map view, it is frequently the case that at the end of one song, the next song won't start playing. Pressing "menu" usually starts the next song playing.
Also while playing MP3s on an SD card while in map view, it is frequently the case that nudging the knob to the right to get to the next song doesn't work. If I press "menu," I'll hear the beep and the next song will play.
This feels to me like a simple software issue for which there is no fix available to us mere mortals, but it is annoying.
