Sound settings panel empty on 12.04

Solution 1:

I found a solution to my problem. My PulseAudio daemon wasn't working.I noticed it when I tried to run pavucontrol tool. There was missing shared library libpulse-common (I had older version of this lib installed).

The problem was caused by the fact that I added PPA of Ubuntu Audio Dev team (ppa:ubuntu-audio-dev/ppa) to my software sources. I did some reinstallations of indicator-sound and pulseaudio package and somehow libs went out of sync.

How to solve it:

1. Uninstal pulseuadio package sudo apt-get purge pulseaudio
2. Remove audio dev team PPA sudo ppa-purge ppa:ubuntu-audio-dev/ppa
3. update source list and get new packages sudo apt-get update then sudo apt-get upgrade
4. install pulseaudio again sudo apt-get install pulseaudio
5. reboot sudo shutdown now -r