[HELP] Weird Slowdown Issue

Hiya folks,

I'm gonna cut straight to the chase: I was playing Crisis Core and i decide to exit a little... I play Prince of Persia and then go back to Crisis Core and all fo a sudden the fights lag a LOT... Like I've never seen before... So I pandorize my psp to clean it and its still slow... What's wrong?

p.s. - GAME is set to 333/166

Thanks to all those who decide to try and help

Is it a CSO file?. I had the exact same problem with my 16 gb card. games like ridge racer, god of war, initial d where slowing down on my psp. I uncompress CSO and they run at full speed.