Lubuntu mute/unmute button problem

I noticed a problem with my keyboards mute/unmute button. It seems that it only mutes, but the solution is simple.
Do the following, edit the .config/openbox/lubuntu-rc.xml with nano.

sudo nano .config/openbox/lubuntu-rc.xml

scroll down untill you see this

<!-- Keybinding for Volume management -->
  <keybind key="XF86AudioRaiseVolume">
    <action name="Execute">
      <command>amixer -q sset Master 3%+ unmute</command>
    </action>
  </keybind>
  <keybind key="XF86AudioLowerVolume">
    <action name="Execute">
      <command>amixer -q sset Master 3%- unmute</command>
    </action>
  </keybind>
  <keybind key="XF86AudioMute">
    <action name="Execute">
      <command>amixer -q sset Master toggle</command>
    </action>
  </keybind>

and type in the following: -D pulse after the -q so it looks like this

<!-- Keybinding for Volume management -->
  <keybind key="XF86AudioRaiseVolume">
    <action name="Execute">
      <command>amixer -q -D pulse sset Master 3%+ unmute</command>
    </action>
  </keybind>
  <keybind key="XF86AudioLowerVolume">
    <action name="Execute">
      <command>amixer -q -D pulse sset Master 3%- unmute</command>
    </action>
  </keybind>
  <keybind key="XF86AudioMute">
    <action name="Execute">
      <command>amixer -q -D pulse sset Master toggle</command>
    </action>
  </keybind>

reboot and done!