I'm running gnome-packagekit-0.3.11-1.fc10.i386 from Fedora 10 updates-testing.
Some menu entries are not translated, these two are the ones I noticed: Software Updates and Software Sources. The interesting thing is that I'm certain these have been translated before (I'm running the fi/Finnish locale myself). If I take a look at the files, /usr/share/applications/gpk-repo.desktop and /usr/share/applications/gpk-prefs.desktop actually don't have any translations in them at all.
If I do an msgunfmt on the gnome-packagekit.mo file of the fi locale, I can see translations provided for those two menu entries. I'm just guessing here, but maybe something has been changed with the build setup and it's not building the .desktop files correctly?
I checked the Makefile.am's, configure.ac and such and they looked good as far as this issue is concerned. Then I built gpk from git and all the desktop files had (some/Finnish) translations. So I also rebuilt gnome-packagekit-0.3.11-1.fc10.i386 from srpm and even all the desktop files produced by that build had translations! As a final test I installed gnome-packagekit-0.3.11-2.fc10.i386 from Koji and the translations are there as well.
I can't understand what has gone wrong, maybe something with the Koji build which produced gnome-packagekit-0.3.11-1.fc10. If you eventually push gnome-packagekit-0.3.11-2.fc10 into F10 this should be fixed, so I'll close the bug.