Need assistance running the latest UMD games on a M33 PSP

Can anyone help me out as I need some advice on running the more recent UMD games for a PSP that's running M33-6 with the latest version of Torky's plugin.

Basically, it seems to be hit-and-miss when it comes to running the following games:
  • Final Fantasy IV: The Complete Collection (continuously stays at load screen)
  • Gods Eater Burst (doesn't work at all)
  • Dissidia 012 [duodecim] Final Fantasy (doesn't work at all)
  • The Third Birthday (works)
  • Lord of Arcana (works)
  • Tactics Ogre (continuously stays at load screen)

Does anyone know how I can downgrade to as well as install a more recent CFW that will let me run the latest UMD games as well as ISO's of games like Dream C Club and Kamen Rider Climax Heroes.