Originally posted by iphone4g4g
Exactly as Poloki said. Rename the folder so it's just:
CUSA09171
and nothing else in the folder name.
Directly inside of the folders you should see nothing but game files. If it's instead more files, which sometimes happens, just keep digging until you find the main game folder which contains game files and nothing else. And make sure its name is ONLY the CUSA number.