There is this strange thing... when I turn on my EEE sometimes there is no sound at all, sometimes there is no sound in zsnes emulator and real player and sometimes there is full sound. Why..?

What is more my alsamixer sometimes shows everything (front mic, capture etc...) but sometimes (when there is no sound for example) it shows only 3 bars (i think they're capture digital and...something ;p )

help...

EDIT: also - sometimes when I try to do Fn + F7,F8,F9 - it doesn't work (I can see the bar changing but no effect with the sound)