I've had this unit for about a year and so far it worked fine, until a few days ago. Now the Nano constantly has the charging battery icon, regardless of whether it's plugged in (either USB or AC). Also, I cannot turn it off completely - when I shut it off, it continues to show the charging battery icon. Tried resetting and restoring and neither works. The battery ran down to nothing and when I recharged it the problem doesn't go away. Any thoughts? Besides this problem it seems to work normally. Thanks