I just found that the lock screen on my laptop does not show up when the right click menu is open. I discovered this when I pressed the right click button accidentally while closing the lid and the laptop went to sleep, but the lock screen never showed up when I opened the lid again. I am also not able to lock the system manually(with ctrl+alt+L) when the right click menu is open. Is this by design or is it a bug? I would assume that the screen should be locked automatically when the computer goes to sleep, but this doesn't seem to be the case. Anyone have any suggestions? My specs are: Dell Vostro 1500, Ubuntu 12.10