Comment 6 for bug 4502

The following worked for me:

1. Click with the left button of the mouse on the volume applet and drag the volume slider all the way down; volume is muted with respective graphical change;
2. Slide the volume back up and the volume is unmutted as expected;

Then, I tried a different approach:

1. Click with the right button of the mouse on the applet, and select the Mute option; volume is muted with respective graphical change;
2. Now, with the left button, you cannot move the volume slider for it is locked in place... I believe that the volume should be unmutted if the slider is moved upwards;
3. Right-clicking on the applet and unchecking the Mute option made everything go back to normal.

To finish the triage, I then tried the last scenario here presented:

1. Double click the volume control icon to make the mixer window appear.
2. Drag any slider (master, PCM, etc.) down to zero. The channel becomes muted (the "mute" symbol appears below the slider).
3. Drag the slider back up from the zero position.

Everything worked as it should...

Am running Ubuntu Dapper (latest) with gnome-media 2.13.92-0ubuntu1 on AMD64 as well.