Trouble with Nvidia 8600M GT and Bootcamp

So I got the macbook pro 2.4 for DJing mpeg2/.vob music videos using
Virtual DJ. Right now Virtual DJ for Mac isn't quite up to par so I'm forced to use it with Bootcamp. When I'm playing my videos using the Virtual DJ the video is constantly freezing and jumping (back and forth) while the audio remains fine. I used this exact same version of Virtual DJ with the previous Macbook Pro that had the ATI 1600 card and the videos played back perfectly.

Even if you don't know about Virtual DJ maybe you could still help me. What could be the difference between the ATI 1600 card and Nvidia 8600M GT that could be causing this problem. My friend who's a little more computer savy then me said that the problem is that Nvidia runs with Directx10 and the ATI card runs with Directx9 and he said Virtual DJ is only compatble with Directx9.

Could anyone help me out?

Your friend is mistaken. DirectX10 capable GPUs run DX9 just fine.

It could be an issue specific to your program, and the video card itself... Might also be a driver issue. If I were you, I'd try and look through some Virtual DJ forums to see if others are having your same problem.