Update. January, 2015 - fix for a libmatemixer problem

I updated my system and its software packages. It was easy.

The only problem: output volume slider was broken. The symptom: movement of the slider does not change volume of the output signal.
I fixed this problem using only the next command:

% cd /usr/ports/audio/libmatemixer ; sudo make config reinstall clean

Checked the ALSA option.
(Re-login to your system after the command finished of executing)