DON'T BUY!!! i've had two of these from amazon and both had the same fault. The micro-usb on the back is not well built and comes loose inside the case making it unusable. The sound quality was great but it's a really rubbish build.
chlbutteworthThis started happening to me today as well. I'm going to tear it open later tonight or this weekend and see if resoldering the usb connection fixes the problem.