I have jailbroken 5 iphones. I just replaced my iphone with Apple Warranty. When i try to jailbreak it, its stuck after DFU mode. All I get is a black screen. I used redsn0w and its stuck at "waiting for Reboot". I also used pwnage and itunes does not detect. I have itunes 8.2. I dont think the new iphone 3G was ever activated through AT&T. Please help!