Comment 5 for bug 1173936

Seems that gnome-screensaver is missing from previous upgrades (12.04/12.10) to 13.04.

As per this article (http://askubuntu.com/questions/292227/ubuntu-13-04-not-locking-screen) it works if you do this:

sudo apt-get install gnome-screensaver

Hope this can be addressed by the Ubuntu lords.

Thanks!