So, now that I have my new iPhone 4, I am selling my 3GS. The buyer I found, however, requires it to be jailbroken and unlocked. Shouldn't be a problem, right? I have jailbroken things before (including this phone). The problem? I can't seem to get anything to work! It currently has iOS 4.0, so I tried the pwnage tool, created a custom ipsw, but couldn't get the iPhone to restore to it. I tried to downgrade to 3.1.3 by downloading the ipsw file and restoring from iTunes. No dice. It always says it can't do the restore. I checked my boot file, it's the old one, so there shouldn't be a problem with that. I just don't know what the problem is! I'm on a mac by the way...