Comment 4 for bug 298790

Thanks for your help! I followed the instructions at
http://ubuntuforums.org/showthread.php?t=789578
and it did not do the trick. In fact, I couldn't even complete the last step, which was to do
$ alsamixer -Dhw
it gives me this error:

ALSA lib simple_none.c:1520:(simple_add1) helem (MIXER,'Headphone Playback Switch',0,2,0) appears twice or more

alsamixer: function snd_mixer_load failed: Invalid argument

I ran alsa-info.sh, like https://wiki.ubuntu.com/DebuggingSoundProblems told me to do, and the results of that script are here:
http://www.alsa-project.org/db/?f=a8f5d58fbe3036963170e397e7c317ef90a39fc2

The computer behaves as if the sound is working. I can "play" mp3s and so on, but no sound comes out of the speakers or headphones (if I plug them in). It seems like the sound is mysteriously muted, but with no way to un-mute it. By the way, the sound also doesn't work on openSUSE 11.0 gnome liveCD or Fedora 10 liveCD (same symptoms, or so it seems)