We have a group policy in place that after 10 minutes of inactivity the users screen will lock for security purposes. In XP if the user saw their screen start to fade out to lock they could just move their mouse to keep the current screen up. For supervisors they do a lot of monitoring that does not require them to interact with the keyboard or mouse.
In Windows 7 (x64) the screen will auto lock after 10 minutes and once they see the screen start to go black moving the mouse does not stop the lock process.
I realize that this is making systems more secure but is there a setting that will allow the movement of the mouse or hit space bar or something to stop the lock process?