Comment 59 for bug 496616

I've been experiencing this issue and wrote about it in bug #532586. This seems to me to be the same bug. In my case, it's only occurring when I switch one of my 2 desktop PCs over to outputting 5.1 analog surround sound. The other machine uses 5.1 without any problems.

On the problematic machine, I dual boot Ubuntu 32 bit and 64 bit and both were affected. However the problem appears to have suddenly disappeared on the 64bit Ubuntu. For the last few days, I've been playing DVDs and watching flash video through 5.1 analog output and haven't been able to trigger the problem once. I was still able to trigger it this afternoon on the 32bit Ubuntu after just 10 minutes of watching a DVD with surround sound set to 5.1 analog. I then switched to the 64bit Ubuntu and watched the same DVD movie without a hitch. Yesterday, I was able to watch over 2 hours of flash video on YouTube without triggering the bug. Before, it only took a minute or two of playback before the audio would disappear.

Everything on both Ubuntu installations is the same with the exception that I've been using the latest Alsa driver modules on the 64bit Ubuntu, which I installed some time ago using the instructions here: https://wiki.ubuntu.com/Audio/InstallingLinuxAlsaDriverModules

Initially, when I first installed the new modules, I saw no effect, but I kept monitoring it since new updates were coming in every few days. Once I realized that the problem may have gone away, I halted the alsa module updates. At this time, I'm using the module with the version number 2.6.32-24.201009201600.