Manually locking the screen interrupts the automatic screen off

[Kevin]

When manually locking the screen with the keyboard shortcut or choosing from the system menu the screen never turns off after the set time (5 minutes for me). When I unlock the screen after the alotted time the screen immediately turns off; pressing a key brings up the lock screen again and entering the password here unlocks as expected.

Ubuntu 14.04 64bit

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: gnome-screensaver 3.6.1-0ubuntu11
ProcVersionSignature: Ubuntu 3.13.0-22.44-generic 3.13.8
Uname: Linux 3.13.0-22-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.14-0ubuntu1
Architecture: amd64
CurrentDesktop: Unity
Date: Fri Apr 4 11:40:16 2014
GnomeSessionIdleInhibited: No
GnomeSessionInhibitors: None
GsettingsGnomeSession:
 org.gnome.desktop.session session-name 'ubuntu'
 org.gnome.desktop.session idle-delay uint32 300
InstallationDate: Installed on 2014-04-01 (2 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Beta amd64 (20140326)
ProcEnviron:
 LANGUAGE=en_US
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-screensaver
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.