I have an unlocked iPhone 3G I purchased off eBay new about a year ago. Today I accidentally upgraded my phone to the most recent firmware in iTunes (3.1.3 I think).
I've looked on the internet and it seems like there isn't a hack for the most recent firmware. Is it possible to revert back to my previous firmware? Right now when I start all I get is a Insert Valid Sim/Connect to iTunes screen.
Any help would be greatly appreciated. :)