My friend just bought a new non-iDevice and he's giving his old iPhone 4 to his father, of which he would like to restore his phone back to factory iOS 5.1.1 His phone is currently on 5.1.1 and he has it jailbroken. We tried going into Settings > General > Reset > Reset All Settings but no avail. We tried restoring the iPhone to iOS 5.1.1 on his MacBook Pro running OS X 10.8.2 with iTunes 10.7 only to get Error 1600 which almost expected because iOS 5.1.1 is no longer signed with Apple for activation. We followed the iOS 6.0 to 5.1.1 downgrade method by using Rensn0w 0.9.14b2 to create our own custom restore using his saved 5.1.1 SHSH BLOB, we put the iPhone into Pwn DFU mode and still managed to get Error 1600. We then figured this method is probably designed to be used from an iPhone on iOS 6.0, at this point we decided to use his MacBook (as we've altered the host file on his currect MacBook Pro). His MacBook is running OS X 10.6.8 and iTunes 10.7, we put the iPhone into DFU mode and tried to restore to iOS 6.0 only to get an error telling us The iPhone not eligible for requested build. I'm really at a loss here, we just spent the last 3 hours trying to do this and we can't even upgrade this iPhone to iOS 6 let alone restore it, it's stuck on iOS 5.1.1 with all of his information and no way to restore. Any ideas?