Not every translation got copied to unity-control-center in Dutch, possibly other langs

gnome-control-center does not appear fully translated, even though it is fully translated in launchpad. For example, the following string from the Appearance tab has been translated in launchpad since 2013, but still appears untranslated in an up to date install of trusty.

https://translations.launchpad.net/ubuntu/trusty/+source/gnome-control-center-unity/+pots/gnome-control-center-unity/nl/+translate?batch=10&show=all&search=Add+show+desktop

One thing that might be related is the switch from gnome-control-center to gnome-control-center-unity. This bug is filed against gnome-control-center, since gnome-control-center-unity is not installed on my system. However, gnome-control-center-unity is what is listed as the template to translate in launchpad.
gnome-control-center also exists in launchpad, but it keeps timing out so I can't check the status of that string, see: https://translations.launchpad.net/ubuntu/trusty/+source/gnome-control-center/+pots/gnome-control-center-2.0/nl/+translate

I encountered this problem for Dutch, I'm not sure if it exists for other languages

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: gnome-control-center 1:3.6.3-0ubuntu56
ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9
Uname: Linux 3.13.0-24-generic i686
ApportVersion: 2.14.1-0ubuntu3
Architecture: i386
CurrentDesktop: Unity
Date: Mon Apr 21 10:01:29 2014
InstallationDate: Installed on 2013-08-04 (259 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release i386 (20130424)
SourcePackage: gnome-control-center
UpgradeStatus: Upgraded to trusty on 2013-12-21 (120 days ago)
usr_lib_gnome-control-center:
 activity-log-manager 0.9.7-0ubuntu14
 deja-dup 30.0-0ubuntu4