(bug originally reported at https://bugs.launchpad.net/bugs/379007) " I encountered this unexpected behavior on xfce4-mixer applet on XFCE running Ubuntu. If you press on the mixer applet icon, a its property window will appear. Doing the same again, will open a NEW property window even when a similar window is already open. It's not a show stopper, but the behavior is not what I expected: displaying or activating the previous property window instead. " I don't know if this is easily feasible though, since the applet dialog is only spawning a given command… Thanks!
I looked into doing that, but is seems you require a external dependency or some C code to hook into window manager properties. Came up with a quick workaround make a script #!/usr/sh for line in `pgrep -x xfce4-mixer` do kill $line -15 done xfce4-mixer Then change the panel properties to launch the script instead of the mixer directly. If will kill all running instances of the mixer and then launch one.
Fixed in commit 88fb4e4474e507575b5b7bf6b4486a04cf573e0f.