It looks like a problem with ACPI. Check out bug #173519; this may be a duplicate.
-- Screen is not locked when laptop lid is closed https://bugs.launchpad.net/bugs/156226 You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is a bug contact for gnome-screensaver in ubuntu. -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
