I had a jailbroken iPhone 4 that was running 4.?.?. I wanted to update to ios 5 so I tried a restore which froze up. Now my phone is in limbo. I have tried all the tricks suggested in forums (it will not enter DFU mode, I commented out the 18.104.22.168 gs.apple.com line in my host file which elimintated my iTunes errors but still no restore, I tried tinyumbrella a little bit, etc.) I'm not looking forward to buying a new phone. Can anyone help me?