Binary package hint: transmission
It seems (well, I've been wrong before but...) that Transmission's .desktop file does not get X-Ubuntu-Gettext-Domain added in the build system for some reason, possibly because of something being non-standard. An installed /usr/share/applications/transmission.desktop does not contain the tag, so that translations for the .desktop item are not retrieved from the language packs.
I built a fixed version at my PPA, debdiff attached. It does not use any patching system, so the .desktop.in change is directly in the .diff.gz. Dsc at http://ppa.launchpad.net/timo-jyrinki/ubuntu/pool/main/t/transmission/transmission_1.06-0ubuntu4.dsc
Installing the built packages fixes the issue for me. Before this version I tried a simple rebuild (ubuntu3build1) of the current source, but the tag was not added.
Michael: can you take a look at it?