Hi. Any help appreciated. I have a 3GS jailbroken and unlocked on 3.1.3, on a non-AT&T carrier with no blobs saved as far as I know (friend jailbroke it on a different computer) I'd like to upgrade to 4.0 to maintain my unlock and fix some wifi issues. How can I do this? It may help to mention that i currently do not have a valid AT&T sim and AT&T is unavailable where i live. I can possibly gain access to a non active AT&T sim at a later date though. I understand that even if I could find a 4.0 firmware file I'd still have to trick iTunes into thinking that 4.0 is the latest fw. And once i get the phone on stock 4.0 that I'll need an AT&T sim to activate. I know there is probably a way of doing this, but I only have one shot at this and don't want to screw this up. Thanks for any help.