I can't seem to make any of the ISO's work. The screen just turns black after the PSP sign disappear. This goes for all the PSP games I intended to play. I don't have any problem playing PSX games, though. I bet it has something to do with the settings, that is why I am asking yours. Before, when my PSP's fw was custom 2.71, everything goes smoothly. I'll just use DevHook and HEN-C enabler. I removed all of it since upgrading to 3.03 oe-c since its completely worthless anymore. I know I am not alone in this problem when I say this, but I am alone though to whom I should go to.

well theyre a very good option that u could do
Put a umd(any umd exxcept a umd movie) and disable use no umd in recovery mode because for some reason u need a umd in the drive to play most games

yeah i just have everything on default and make sure a UMD is in the drive.

The only game I have that doesn't work is ratchet and clank, but i see that you have to change the CPU speed, but I don't know if i want to mess with that or not.. *shrug*

yes you have to increase the cpu speed to play ratchet and clank, it took me 4 iso downloads to figure that out. increasing the cpu speed isnt bad for the psp it just uses the battery faster. and you could always change it back when you arnt playing ratchet and clank. and like has been said i too have everything on default and just have a umd in to play everything.

No worries on the cpu speed mate, just into recovery (power all the way down, power on while holding right trigger) I think i have seen ratchet and clank play @ 266 but you can play with it...