Freezing Problem.

How come every time I open my Dj Max Portable 2 to play freestyle mode/4-button/5-button challenge my PSP will freeze? I don't know how or why it happen but I was hoping I could fix it again... I don't know what the problem is! I know it's not about the PSP because my other games are playing well. Well, I'm really naiinis right now... I don't know how to fix it! =(

I wish I could find solution 'cause I'm trying to google it. But, I can't find any answer for it. It's an ISO file...

HELP! HELP! HELP!