I have an x710BT and I loaded up some mp3 files on my 16 gig Class 10 card. It recognizes and begins playing, however, as soon as music starts to play, the whole unit freezes up, and i cannot use the touchscreen, menu/map buttons. Does anyone know if this would be because of the memory card size? in the specs, it does mention unit maxes out at 8gig cards. any insight?