Comment 84 for bug 1311316

I don't know if it helps, but I always had problems like "no input field for password" or the "double unlock" (if the first problem does not occur, unlock presented another unlock field with a sightly different screen) problem on my notebook. Then I noticed, I have a package installed named "light-locker" (I am not sure about the name though, just by heart now). After removing that package I had no problem like these since then! Since I've installed meta-packages xubuntu-desktop and lubuntu-desktop as well (so I can test different desktops) it can be a reason as (if I am correct) these packages depends on light-locker. Removing them caused those meta packages to be removed as well (again, if I remember well enough), but at least since then I have no problem with regular ubuntu (unity) desktop locking&unlocking.