GNOME Bugzilla – Bug 687678
gdm lock screen is unresponsive for keyboard input
Last modified: 2012-11-12 15:19:10 UTC
How to re-produce: Lock the screen. Wait till screen turns off. Then press "Enter". The lock screen with the clock disappears. But do not show the prompt to enter password. Screen is unresponsive to any keyboard action. (Can not even move into command line consoles.) Mouse is responsive. (Can change the volume.) How to come out: Close the laptop lid. Wait till machine suspends. Initiate machine again.
This doesn't happen anymore.