Alright so click this link http://dl.qj.net/IvEr-PSP-v2.00-PSP-H...
download VERSION 2.00 it looks like an itouch but just ignore it I cant really explain how but this kid tells you on this youtube video. its very helpful
YouTube - How to play new psp games on old psp cfw versions / Update Gate Bypass (CFW) (IT TELLS EVERYTHING)

----Added 7/5/2009 at 4:07 PM----
Quote Originally Posted by Sneaky Poptart View Post
If your still using NitePr, then go into the NitePr folder (which is in your seplugins folder) and add a text document and label it the Game ID for Resistance Retribution (which in this case would be UCUS-98668). Then open the text document and copy and paste the codes in there. That will be your database of codes for that game.
would i have to plug in psp or nite pr saved on pc?