It is also fixed for me (but before gnome-screensaver didn't fix it), after upgrades (don't know what packages).
** Changed in: gnome-shell (Ubuntu) Status: New => Fix Released -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1215816 Title: CTRL+ALT+L dont lock screen on Ubuntu 13.10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1215816/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs