Hi, my iPhone 3GS 8 GB is having some weird sound issues. I had the volume on I'd say about 3/4 the way up, maybe half, but anyway when it was locked and it got mail, it made the mail sound and then this ch ch chch chch chchchchchchchchch sound, kind of like feedback IMO. It got from slow to fast and medium loud to louder than I had it set. I've done a restore, but it happened again. The first time, it was whenever I played a game and then locked it and now when it gets mail. Should I be concerned? Thanks!!!