Unable to change volume

Just did a clean installation of OpenSUSE 13.1.
At first Skype calls did not work ("audio problem"), but then i managed to fix it, probably by installing PulseAudio ALSA plugin.
Then, after I had been messing with audio, i noticed, that I could not change volume.

Hardware volume buttons do nothing (worked before).
Tray menu shows this:

moving two upper bars plays "ding" with constant volume no matter what position.

What should I do?
or
What information would be relevant to You in order to look into this problem?

Thanks for Your time,
ervion

NOTE: Audio in fact does work, both recording and playback, that means working Skype calls etc., simply volume does not change.