This seems to be fixed in PulseAudio 0.9.7, as long as I use the
pulseaudio mixer in System->Preferences->Sound. Yay!
** Changed in: pulseaudio (Ubuntu)
Status: Confirmed => Fix Released
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Unable to effect alsamixer -c 0 changes when pulseaudio is active
https://bugs.launchpad.net/bugs/
More concretely, the problems when pulseaudio is running are:
1) There's no way to change the global volume: the gnome-volume-applet and the
volume hotkeys sliders appear to work, but don't change the volume at all with
the (exception of mute). This is with any of the available mixers: ALSA, OSS
