I receive message, “Cannot copy…The device has either stopped responding oe has been disconnected.” I use the device for audiobooks. Short transfers (<200MB) sometimes complete but if I attempt a second book it will disconnect and because it hadn’t finalized I lose both. Usually, but not always, it freezes at this point. Occasionally it opens and resumes charging. I own 3 clipzips and have the same problem with all of them. They’re 3, 2 and 1 year old. Any suggestions?