xfce4-mixer-plugin crashes on mouse scroll: problem and fix

List-
  Well found an interesting problem and solution. It appears that when
you add the xfce volume panel applet on a machine that has not used it
before it likes to crash. The cause is that it fails to deal correctly
with a missing configuration file. There is a patch for it at
https://bugzilla.xfce.org/show_bug.cgi?id=7630#c4. The work around is
to after adding the applet use the panel items edit button to make a
change to trigger a config gile creation.

Evan