Comment 92 for bug 352732

I'll add my vote for #77 as well. Before I tried this solution, I ran the following experiment: I got all my settings the way I wanted them. I started alsamixer to monitor the settings, then I killed /usr/bin/pulseaudio. When the daemon restarted, it muted the audio. This tells me the problem is entirely in pulsaudio.

Now I had thought I had fixed the problem for a couple of weeks by setting alsa-utils to run at system startup. Whatever bug pulseaudio gets up its arse just comes and goes to reasons currently unknown, so just because it goes away when you fiddle with alsa-utils doesn't mean you've found the problem.

The issue with alsa-utils, as far as I can tell, is that ubuntu sets up the stop script to run, which saves settings and mutes, without setting up the start script to run. You need both or neither. Deleting the line that mutes doesn't really fix this. It happens to work when you re-boot because the hardware probably doesn't get reset. I'll bet that booting to another operating system with different settings or possibly even powercycling will cause other, harder to diagnose problems.