I've upgraded to a 1520 but kept my 920 to use as a media player/backup phone just in case. I've been able to add music and things to it just fine until today. Can't connect to the app store at all, hasn't gotten any update notifications, and I'm unable to transfer music to it from my desktop. Windows Phone app just keeps giving me errors. Has anyone else had this issue? Surely it can't be because it doesn't have an active SIM in it, can it?