I have a 3G S on 3.0.1 and it's jailbroken. However it's playing up and I need to send it off to Apple. Incase something happens (my luck) and they wont fix it and return it I want to be able to jailbreak again. When I try to restore it with the 3.0 firmware or the 3.0.1 it says it cant as its not a registered build or something. Anyone know How to do it? Thanks!