We have a few customers who have experienced every glitch there is.

I probably have in the vicinity of 4,000 actual power-on playing hours on my Mark 2 player, and have had a total of one "problem" with it. I had it installed on my bicycle (really!) and the wind blew the bike over when it was parked. The impact loosened the hard cable connection. Reconnected the cable, added a bit of hot glue, and everything has been fine since.

tanstaafl.