Alright, so I accidentally saved over my brother's Final Fantasy 13 file. Not a problem, I can just get back up to where he was. However, he maxed out all his characters, so I thought I might be able to jailbreak the PS3, hack in infinite EXP, and just get everyone back to max.
Is it possible, once I've done this, to un-jailbreak the PS3? My brother and I aren't interested in keeping it around, I just want to get this done quickly and then put everything back to normal. Is this possible, or are there permanent ramifications of jailbreaking? For example, if I undo the jailbreak, will we be able to access PSN normally and receive updates from Sony?