I have a 3g Iphone. The vibration suddenly stop working for 1 weeks now. I try to restore the iphone many times but it won't help. Do you think if I bring the iphone to apple, would they replace it for me? My phone is still under warranty. The other issue I have is I don't have ATT account. I am using Tmobile.So what should I do when the genius people ask for my SIM card. Can I tell them that I only use my iphone as an ipod to listen to music? Or should I buy the prepaid ATT sim card? Please help me. Thanks a lot.