I don't know if this was posted already, I'm quite a noob when it comes to this stuff, but my PS3 is running the 4.21 firmware. Is it possible to revert back to 3.55 or previous, or even to just erase the 4.21 firmware and install something like 3.55? I want to do it because I want to be able to play backups of my games. At $60 per game, I can't afford for them to get scratched up and have to shell out another $60 for them. Plus my cousin and I trade PS3 games around once in awhile to try out games we haven't played. Anybody know how to do this? I see all these things for customized firmware, but I don't know if it can be done with the firmware I have. Most of the downgrades I have found are fraudulent/spam.