Comment 221 for bug 192888

Here is the step-by-step process by which I was able to get Firefox working with flash beta 10 + pulseaudio (it stopped the crashes - yay!). In this tutorial I've merely cobbled together in one place suggestions scattered around on this forum.

http://wvarner.blogspot.com/2008/05/firefox-crashing-on-youtube-in-ubuntu.html

Hope this helps!