Keep losing my volume control?

[Andrew Robinson]

I have the volume control plugin added to my xfce panel. At times (not
sure exactly when), it keeps disappearing on me (no longer in the
panel). When I re-add it, it goes back to the default settings
(wannabe master and device are no longer set to my previous settings).

Any ideas on this problem?

xfce4-panel 4.4.1-1-ubuntu3
xfce4-mixer-alsa 1:4.4.1-3ubuntu1

Thank you,
Andrew