Hello,
I've been a Vegas user for years.  I've never had any issues with Vegas before.
I recently upgraded to 8.01c on my new Intel Quadcore.
My audio is dropping out and distorting in Vegas when video is playing.  Without video (or when I use Sound Forge) the audio is great.
I thought the problem was because I was using onboard sound.  I bought a dedicated sound card but that didn't solve the problem.
I considered that the graphics card may be the culprit so I updated the drivers on it.  It's a geforce 9800 GTX.  That should be plentry of horsepower.
I'm running Windows XP SP2.  I built the machine (as I did all my prior machines) so it's got no extra software running.
I've searched the net and this forum, but no answers.  I'm pulling my hair out here.  Any ideas?