I have an iPhone 3G that I have tried to restore. It was previously jailbroken/unlocked (redsn0w 0.9.6b5). I received the error on iTunes saying it was "not eligible for the requested build". I removed the "gs.apple.com" line from my hosts file, and it attempted to restore. I then received error 1015. Rebooted into DFU mode and tried using redsn0w 0.9.6b5 and IPSW 4.2.1, and it all appeared to go well, but the phone froze when booting. From there, I have been stuck. The phone can be reset into recovery or DFU modes, but I always get error 1015 from iTunes, and redsn0w 0.9.6b5 works except for when it freezes during booting. Any advice on how to solve this issue?