I'm using gnome-panel and not Unity and I can confirm the same bug, that I can't take a screenshot, when I am in a menu of the panel. I experienced this bug when I was trying to report bug #768509.
I'm using gnome-panel and not Unity and I can confirm the same bug, that I can't take a screenshot, when I am in a menu of the panel. I experienced this bug when I was trying to report bug #768509.