My iPhone is a 16gb 3GS on 3.1.3 and baseband 3.12.01. I just got it replaced at the apple store. When I get a call, whether its on silent or not, keeps vibrating even after caller has hung up trying to call me. The phone wont stop vibrating and shows the callers I.D infinitely untill I slide to answer, if I dont slide to answer it will keep going and going so if I get a call and im away from my phone wont stop untill I slide to answer. I can here sounds if I get a text or email but not for when I get a call. I have tried resetting the phone using both buttons, resetting network setting and resetting all phone settings. Can anyone shed any light on this?