[PROBLEM] No Mute?

[namtih]

I've mapped the Mute function to a button of my remote:

Code:

<keymap>
  <FullScreenVideo>
    <keyboard>
        <equals>Mute</equals>
    </keyboard>
  </FullScreenVideo>
</keymap>

When I push the button now, it's recognized by XBMC, action is "Mute" and I see the Mute icon:

Code:

15:00:51 T:3042426880   DEBUG: OnKey: equals (f03d) pressed, action is Mute

But the sound is still playing and not mute.
Am I missing something? Is Mute working for you?