Hey, Im on 3.1.2, or 3.1.3 i don't remember, Im using an iPhone 3GS jail broken with blackra1n. Im trying to use a custom 4.0 FW i made with pwnage tool. Everyone says it'll work once I'm on 3.1.2 or 3.1.3. I go to restore on my MAC 10.6 with itunes 9.2 but then I get error 1604. So I cant get it to restore, I'm trying to revert back to a clean 3.1.2 but iTunes says its going to verify the firmware and then says my iPhone isnt eligible for this firmware. how do I fix it or get rid of the 1604 error?