it's been working fine, but for the last couple days, every few hours or so, the lock button would stop working!!!! I would have to keep on pressing it to get it back on track!!!! Right ive been pressing it for hours and now, it is completely useless!!!!! ...CAN SOMEONE PLEASE HELP ME I'VE BEEN SEARCHING AND TRYING, AND I REALLY DON'T THINK IT'S BROKEN!!!!