Comment 7 for bug 619663

"Interestingly" If I set the external monitor to be full resolution and tell the gnome-display-properties to turn the laptop panel off, thus giving me full screen external display all is fine. However if I then choose to turn the laptop display back on and enable it, the laptop display is blank, however it's clear that gnome 'thinks' it's active because the panels disappear from the external display - presumably being displayed on the blank laptop panel. Of course if I switch the laptop panel off again the panels come back to the external display.