When I just start a guest session and switch back with Ctrl+Alt+F7, my session is indeed locked. So it seems that the indicator does its job, and as you say, lightdm seems to unlock when using ConsoleKit to switch back?
When I just start a guest session and switch back with Ctrl+Alt+F7, my session is indeed locked. So it seems that the indicator does its job, and as you say, lightdm seems to unlock when using ConsoleKit to switch back?