since kaffeine 1.3 I notice that the GUI ( menus ) is only in english, it's not normal because with the previous version (1.2.2-4 ) kaffeine automatically choose the right language ( in my case : french ), the language files ( *.mo files ) are missing the package, for example we should have many "kaffeine.mo" files for each language in "/usr/share/locale/kde4/*/LC_MESSAGES", but in the 1.3-1 version these language files are missing, why these kaffeine.mo files are missing ?
Language files are no longer needed with Kaffeine. Try for example "sudo apt-get install --reinstall language-pack-fr-base" or http://packages.ubuntu.com/search?keywords=language-pack-kde-fr
kde-l10n packages only contain translations for the KDE Applications release. Kaffeine is in Extragear, so it must ship its own translations like all other extragear applications.
If you Install it from the source files and follow the instructions at the README file, on Kaffeine 2.0.1, you should get the translations. If you're using a version from a distribution, then you should open a bug at the distribution's bugzilla asking them to package the translations too.