said by anonnnn :
So there must be some setting for locking an idle computer that is NOT related to the screen saver and yet nobody knows where it is?
I guess I'm nobody, since I know where it is.
Two things may happen on inactivity:
1) Screen saver. May be password protected. See "on resume, password protect" on screen-saver settings.
2) Power management. See "prompt for password when computer returns from standby" on Power Options control-panel applet.