Reply to VCI-300 Sound Problem with ITCH

I just bought a VCI-300, and I am having a few problems. Well, one big problem actually. I've gone through a bunch of threads, and can't find a solution. The problem is that I have no audio coming out of my computers speakers when I'm in PC mode (in Serato ITCH).But as soon as I turn the VCI off, it turns into the "simple" ITCH mode, and I can hear the song fine. It's only when I have full control of the software that I can't hear it. I can hear it when I plug in directly into my amplifier, but there is no sound coming out of the PC. I have an M-Audio fast track pro, but that should not be the problem. I reinstalled everything to do with both of them, and still, nothing. I'm running OSX 10.6.7. If anyone has any ideas, please let me know.