PSP Game Freeze!

[imsry]

When i try to play games especially when there is alot of graphics involved my PSP like to freeze on me. I cannot quit the game but the only option is to shut it down.
I was playing Little Big Planet, but then it froze at the 5 th level. Why is it freezing??? It forze on other games too like Dynasty Warriors. Sometimes i have to make the cpu and XMB speed very low to be able to play the game without freezing as much, but it still freezes sometimes.

Model: PSP Phat 1006
CFW:1.5 -> 3.72 m33 ->5.00 m33-6 -> 5.5 Gen D-2 (games froze on all of them)
Memory Stick: 4GB, MagicGate Supported

I have tried reflashing, reformating , switch diffferent dirvers :sony np66, m33.

Whats wrong with it?

[jxx2005]

try official firmware?