If the audio gets distorted online as well, and in other programs, the pgmusic software likely has nothing to do with the problem.

Check your IRQ table to see if the sound device firewire is being shared with any other device. I don't mean Windoze reporting "no problem" here - it would do that if every device were on one IRQ, bah. You don't want your sound device sharing with anything else, ideally, or at least not with video, network or other high bandwidth device.

To get to your IRQs, go to "Start", "Run", type in "msinfo32" and click "OK". In the left window, click on the "Hardware Resources" plus sign, click on "IRQs" and, after "polling" the computer, it will display what IRQ each peripheral is assigned to in the right window.

--Mac