5.00 CFW Can't read certain sav files

[kurotensaitenshi]

Yo!
Apparently i upgraded my slim into a higher firmware which is 5.00 m33. But now i can't read certain game saves such as phantasy star portable and monster hunter freedom, i tried searching on the forums and see if anyone else had the same problems and they said it was the encryption? data on the save file which can only play on a certain firmware and i would have to start a new game but i don't like starting a new game after i spent so much time playing them. So is there anyway i can change it like for instance to decrypt the hexadecimal data in the iso or sav data so im allowed to load the old game save i have? Any help is appreciated! thanks!



P.S. i have 3 psps', 2 phat (3.90 & 5.05 gen (full)) and 1 slim (5.05) firmwares they are all fully hacked and running. And i know a little bit of decrypting and encrypting files.

[PSPLover]

Have you played rockband recently? it deletes hidden files on your ms making iso's dissapear

have you tried backing up your saves then formatting your memory stick?