Audio Popping/Crackling

[Fender321]

I've done everything I can think of to try and fix this issue. I get popping noises from both live tv and recordings. It happens more when the output is "loud". It sounds like the audio is being overdriven, but no volume bar I can find changes it one bit. The popping sounds always exist.

I have tried 2 different sound cards (Onboard CMedia and Turtle Beach Santa Cruz)
I have tried Win2K and WinXP.
I have played with the sound and video hardware acceleration settings.

I outputted the audio to a different computer, and it was perfect.

Are there any known issues with my hardware?
Radeon 9600 all in wonder
Asus A7V333 MB (KT333)
Turtle Beach Santa Cruz/Onboard CMedia

Could it just be that both these sound cards are just plain terrible or maybe too old?

[grillcheese]

I noticed popping/crackling coming from my speakers when I played the Dave Chapelle dvd. That is the only dvd it has happened on and I dont remember any other situation where I heard it (tv, streaming radio). Theres something about that dvd that causes the problem is all I can think of. Im using an nforce2 onboard to drive audio. Sounds like im fortunate to only have had this happen once...