I use openSUSE 11.2 and sometimes the sound in the Flash player does not work. In the past I used to restart my computer to solve this problem, till one day restarting the computer did not solve the problem. I searched all the net about a solution for this weird problem. It seems many people are facing this problem but nobody writes a solution.
With all the frustration, I decided to kill the process's which I think cause of the problem one by one. I used the mimic version of System Monitor (ksysguard) which is available after pressing Alt+F2 in KDE platform. I kept doing that till I reached to the problematic process “pulseaudio”. Maybe this result does not surprise some of you.
Killing “pulseaudio” process is not the magic solution for all sound problems but it is worth to be tried before you search for other solutions.

I have this issue on a debian
lefty.crupps (not verified) on Wed, 12/30/2009 - 17:11I have this issue on a debian box (Debian Sid, KDE 4.3.4) that I run, and this is the fix I use:
sudo /usr/sbin/alsa force-reload
Its very odd though that I can play sound from almost any source, including Amarok and from various Flash-based websites, but not YouTube without running the above command.
alsaconf
Anonymous (not verified) on Wed, 12/30/2009 - 07:20One way to find the responsible process is to use alsaconf. Exit whatever application is showing you the "volume control" (kmix on KDE). Run alsaconf from a command line as root. If all goes well, your sound will be working, but if your sound device is locked by a running process, you'll see "sound is being used by pid" followed by one or more "pid" values that will let you identify and kill the problem processes.
Thank you for the hint.
Zayed on Wed, 12/30/2009 - 09:47Thank you for the hint.