I can also confirm this happens intermittently on Hardy, all released updates, with nvidia restricted drivers compiz and two instances of X in a dual monitor setup. I believe it only happens on one of the screens when it does happen. I usually manually lock the computer, so it could happen every time that it locks automatically. I will pay more attention.
I can also confirm this happens intermittently on Hardy, all released updates, with nvidia restricted drivers compiz and two instances of X in a dual monitor setup. I believe it only happens on one of the screens when it does happen. I usually manually lock the computer, so it could happen every time that it locks automatically. I will pay more attention.