Lately, I've been having a weird issue. My Clip+ will play fine, but then suddenly stop and do one of two things. Either the screen goes black and I have to hold power to reset, or it jumps back to the beginning of the track. I usually keep it in my pocket with my cellphone, and though maybe something was loose and was being jostled. But, I can hold the player, tap it, shake it, and it keeps going. The problem seemed to start with the latest Rockbox. Tried an older version, and it still does it. It seems to happen like every half hour. Any suggestions? Thanks.