I did a brief search to look for common threads, but didn't find any with the search terms I was using -- my apologies if this is a duplicate. I was having problems with my Galaxy S3 paired to the Model S. When the phone was locked (due to timeout or manual lock), I could not place any calls (it would just silently fail and return to the media screen) nor could I connect to the phone for media choices. This is a known problem with several devices that run Android, in that if you use a pattern or PIN lock on the phone, bluetooth devices cannot start calls or media, regardless of the "make calls even when device locked" setting in the "accessory settings for call" menu of the phone app. In the main settings menu, under "security and lock screen", you must enable the "with swipe lock" option; this lock screen allows for bluetooth connections even when the phone is locked. The downside is that before entering your PIN or your pattern to unlock the phone, you must do a swipe; the upside is that the Model S works flawlessly with the phone.