I had a 3.1.1 jailbroken 3g iphone, I accidentally updated it today to 4.2.1 FW 05.15.04. I don't have an official AT&T sim as I'm in the UK, the iphone can only make emergency calls as of now. I have not tried jailbreaking as I read that the Redsn0w's jailbreak changes FW to ipad and is irreversible. Is there anything I can do to make my iphone functional again without an AT&T sim?
Cheers
Cheers