JPCSP why is it so slow?

[CCFFVIIS]

Hi, I just started using jpcsp yesterday, after that 'fake mpeg vid' problem and the no sound one. So, when I started playing my for so long wished Crisis Core, I realized the action part was really slow, it moved in backlashes, I think 'jiggling' is the word, but again, I'm not English. I already had issues I solved thanks to the people of this site, and I'm really grateful for that, so if you're very busy, just take your time. Thanks, bye.