Has anyone else had an issue with random turn offs when in sleep mode? I put it into sleep mode about once a day (on purpose) while at work and about 1 out of every 3 or 4 times when I go to take it out of sleep (say 8 hours later) it apparently turned itself off at some point. It then boots up and the volume for the different settings are turned down (not how I left it). Any clue why this would happen? Anyone else experiencing this?