Very long time ago (haha) I can't control the main system volume (Gnome volume control) when using volume keys on my keyboard. I realized that many guys are in the same boat.
I've tried to figure out problem in many ways, now I can resolved my issue.
System > Preferences > Sound
then select device and track to control. (Internal Speaker is the one i used.)
Now it works, i can control sound volume on my finger.
edit @ 18 Oct 2007 22:52:48 by Compman