Ok, call me a freaking idiot, but my S3 (Verizon) will at times just ring like there's an incoming call. Yet when I pick up the device, there is no call at all. There's no record of a missed call either in the call log. I believe I checked all my notification settings (?), and the default ringtone is set only as that. Any ideas? It's driving me crazy. Thanks for any ideas.