This might sound strange, but if for example, I am playing a youtube video, and I decide to lower the volume down to 0 (pressing the down volume key-same key as the f11) all the way down-there is still a slight sound. But if i press the mute button-its completely silent. I would have thought that if I press the "lower volume" key all the way down, itd be the same as the mute button...Is this the same for anyone else...?