i just updated my iPhone 2G to the lastes firmware and then i jailbroke it with redsn0w_0.8 and NOW when i connect to iTunes it says "The sim card is not supported"😕
i've done that and iTunes keeps saying that only compatible SIM cards from a supported Carrier may be used to activate iPhone. Any other suggestions ??
No, no, no. You're getting bad advice here. The problem is not your jailbreak, it is the way you're trying to unlock. You have a 2G iPhone. You can't use blacksn0w to unlock. You need to use BootNeuter to unlock your phone. You can install it from Cydia.
I had the same problem, I have a friend that is on AT&T so I borrowed his SIM card just long enough. Once it recognized the SIM card, I was able to switch back to my T-Mobile card and all was good to go. Try it, no harm. Good luck...