Comment 17 for bug 576083

I'm using compiz and was having the same problem. This problem is not only affecting covergloobus and I've found this link :

https://wiki.archlinux.org/index.php/Conky#Don.27t_minimize_on_Show_Desktop_.28Compiz.29

The explanations here solved the problem. Maybe the behaviour can be documented in the covergloobus preference dialog ?
And thanks to the "window rules" plugin of compiz I solved another problem (the windows was decorated).

Another thing I tried was to catch "window-state-event" and to ask the window to deiconify itself, it works too, but this adds a delay to display the window again. The code I tried was just this three lines (if someone is interested somehow) :

inside the window creation member :
        self.connect("window-state-event", minimize_event)

and a function :

def minimize_event(widget, event):
    if event.new_window_state & gtk.gdk.WINDOW_STATE_ICONIFIED or \
            event.new_window_state & gtk.gdk.WINDOW_STATE_WITHDRAWN:
        widget.deiconify()