Can't play UMDs on 6.39 ME-9.4

[Cloud]

Hi there,

I have a PSP 2003 (the Simpsons model) that I recently hacked. It plays ISOs perfectly, but when I try to play my UMD of Dissidia: Duodecim, the screen goes black, and eventually, the power of my PSP turns off.

Is this a hardware issue, or do I need to readjust the settings on 6.39 ME-9.4 to play UMDs correctly?

Thanks.

EDIT: Now it isn't playing an ISO of Dissidia: Final Fantasy, either... I'm just confused now. It loads it but freezes past the Square Enix logo.