Ok. So I had an iPhone 3G that was working on 2.1 - and being excited about the new whizz-bang of OS 3.0 I decided to upgrade. I used redsn0w (2.7) on a MacBook Pro running Leopard, activated Ultrasn0w and all was well. For an hour or so. My phone then froze on the slide to unlock screen and rebooted itself, over and over. So I restored back to stock firmware (thinking that maybe redsn0w was bad for me) and decided to try pwnage tool. Again, worked like a charm, again for an hour or so, then we were back to the slide to unlock, apple logo reboot cycle. Now I can't even restore back to the stock firmware for some reason - when I do, after it has 'restored' and the phone has rebooted it's stuck on the DFU slide for emergency screen for a while and then reboots again! It's driving me crazy. And I cannot think what I can do to get out of this situation. Please, ANY help would be greatly appreciated.