I have a dell laptop with volume up/down/mute keys. After I first installed FC6 i could press these keys in gnome and the little volume control window would pop up and adjust the volume. Somehow, I've lost this and pressing my volume keys doesn't do anything: no little window, no volume change. I checked the System->Preferences->Keyboard Shortcuts to make sure that the mappings are there. I checked that the buttons are still being seem by X using xev. I changed the mappings to keyboard control sequences like <ctl><alt>u but still no volume windows.
Where does this volume window come from? Is there some applet/program that isn't being started that should handle volume changes? Where would I check for this.