So here is the story. I purchased the iPhone 2G in Nov 2008. It was carrier locked to AT&T (obviously) but using a turbo sim I was able to use it on T-mobile. I also jailbroke it. The OS version was 2.0.1
Now, since Nov 2008 I never upgraded the version because the guy who sold it to me said that if i did upgrade I would lose the unlocking that the turbo sim provides. So from Nov 2008 to today June 2011 I've been on v2.0.1.
One more important point - The original AtnT SIM that came with the phone. i lost it and do not have it.
Today, I'm not sure why I decided to connect my iphone to iTunes 10.2 and subsequenly decided to upgrade to 4.2 which iTunes proceeded to go ahead. But what iTunes did was first restore the phone to factory settings v2.0.1. When this happened, it asked for activation and I could not proceed because I do not have the original SIM with me.
So then I did some googling and the nproceeded and using the iTunes restore feature along with Tiny umbrella and restored the OS version to 4.1.2. Now, I'm stuck - I cannot activate it because i don't have the AT&T SIM. I tried the limerain, blackrain, etc. and it sjust does not complete.
I tried down restoring it to v.3.1.3, v2.0.1 - nothing. When restoring, iTunes gives an error saying that the firmware was incorrect and hence cannot restore.
So Now I'm stuck. PLEASE HELP ME!