It may be a little drastic to switch distros. (I've grown fond of Fedora 11 over the past few weeks.)
But you might need to run through some troubleshooting steps: PulseAudio fixes and workarounds
If push comes to shove, you can remove PulseAudio from your system altogether (which is what I did). Those instructions are at the same URL, under the heading "To really remove PulseAudio for some reason".