Controller problem

[tack800]

I have a version 1 ps2 with a dms3 chip installed. All of my backups have been working great, except for Prince of Persia. Both the original and backup don't work. The game boots, but when it gets to the start screen, it is acting like the controller's d-pad is stuck down. I can't turn on the analog control either. It just keeps cycling through the menu. I have used a brand new Sony controller and it does the same thing. Any ideas on what to look for. I am assuming it is my chip that is interfering with it, but like I said, all other games work great.