This isn't really a bug: the LockXLock option works if xlock is installed. Without xlock, you can instead use other locking options (LockXScreenSaver, LockGnomeScreenSaver, LockKDE) to lock the screen if you're already running the appropriate screensaver.
This could be a wishlist request for starting up a locking screensaver if one isn't already running, but it shouldn't be release critical. Eric -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org