Comment 14 for bug 884210

Can also confirm that I experience this same bug. Was surprised to learn from reading the various bug reports that my Logitech E3500 could be the source of the problem, but sure enough the problem seems to be resolved by unplugging the camera.

I am running Ubuntu 11.10, kernel 3.0.0-15-generic-pae

I have been looking for a solution for some time and have been trying various brute force techniques to try to force the sound to work (though sometimes Ubuntu boots with no sound issues, so the problem is not necessarily systematic). I got the impression that the issue may be related to sound permissions because when the bug occurs I can use the "aplay" command only through sudo. Some of my brute force attempts to resolve the issue have been to use the following commands:
 sudo chmod -R a+rwX /dev/snd
 sudo alsa force-reload

I also check alsamixer to make sure my sound isn't muted, which it is sometimes for some unknown reason. Sometimes the above actions work, but not always, so maybe the sound just comes back through luck.