I have a 2010 Ford F-150 with the Sync system and an iphone 4 running 4.2.1. When It's connected via bluetooth, it's like my phone has been muted so my text message alert tone doesn't play, it just vibrates. Phone calls and everything else works fine through the bluetooth connection. I'm missing all my text messages while in the car which is fine while driving but not cool when I am parked or in a drive through line etc. Any ideas?