Problem using keyboard for adjusting sound

[VTill]

Hello, i'm not able to adjust sound level directly by the keyboard.
Problem has comed since Ubuntu 12.04.
I have removed pulseaudio because microphone didn't run for skype due to it.
I have installed alsa driver and alsa mixer tool.
My desktop is gnome.

I could adjust sound level, sourdine direcrtly by Fn + keys.
Could anyone help me please ?

Tx
VTill