Ok this is driving me INSANE! my White 16GB 3GS is cracking along the vibrate button. It is also emitting a high frequency tone when sending SMS! it is driving me nutz. In a quiet room it is all I can hear! Anyone else experiencing this???!?! do you think I will have an issue getitng it replaced? i purchsed it from a local AT&T store on launch day... take it back there or my local apple store?