Only started having this problem recently....about every third day or so some or all email accounts stop syncing. I have a signal, makes no difference if I'm on wifi or not. I have three accounts, Gmail, Exchange and Yahoo and most of the time they all stop syncing. The fix is easy: just put it in airplane mode for a few seconds, then back in regular mode. But it's still a pain and I can't tell when it's having the problem unless I look at the sync times. Anybody run into this one?