You can check if a PO file is valid with the following command:

        msgfmt -c -o /dev/null <po file>
      

The following errors were found in phonon 's PO files:

gettext: poqm/ar/libphonon_qt.po: qt not a language code
gettext: poqm/ar/phononsettings_qt.po: qt not a language code
gettext: poqm/az/libphonon_qt.po: qt not a language code
gettext: poqm/az/phononsettings_qt.po: qt not a language code
gettext: poqm/be/libphonon_qt.po: qt not a language code
gettext: poqm/be/phononsettings_qt.po: qt not a language code
gettext: poqm/be@latin/phononsettings_qt.po: qt not a language code
gettext: poqm/bg/libphonon_qt.po: qt not a language code
gettext: poqm/bg/phononsettings_qt.po: qt not a language code
gettext: poqm/bn/phononsettings_qt.po: qt not a language code
gettext: poqm/bn_IN/phononsettings_qt.po: qt not a language code
gettext: poqm/bs/libphonon_qt.po: qt not a language code
gettext: poqm/bs/phononsettings_qt.po: qt not a language code
gettext: poqm/ca/libphonon_qt.po: qt not a language code
gettext: poqm/ca/phononsettings_qt.po: qt not a language code
gettext: poqm/ca@valencia/libphonon_qt.po: qt not a language code
gettext: poqm/ca@valencia/phononsettings_qt.po: qt not a language code
gettext: poqm/cs/libphonon_qt.po: qt not a language code
gettext: poqm/cs/phononsettings_qt.po: qt not a language code
gettext: poqm/csb/libphonon_qt.po: qt not a language code
gettext: poqm/csb/phononsettings_qt.po: qt not a language code
gettext: poqm/da/libphonon_qt.po: qt not a language code
gettext: poqm/da/phononsettings_qt.po: qt not a language code
gettext: poqm/de/libphonon_qt.po: qt not a language code
gettext: poqm/de/phononsettings_qt.po: qt not a language code
gettext: poqm/el/libphonon_qt.po: qt not a language code
gettext: poqm/el/phononsettings_qt.po: qt not a language code
gettext: poqm/en_GB/libphonon_qt.po: qt not a language code
gettext: poqm/en_GB/phononsettings_qt.po: qt not a language code
gettext: poqm/eo/libphonon_qt.po: qt not a language code
gettext: poqm/eo/phononsettings_qt.po: qt not a language code
gettext: poqm/es/libphonon_qt.po: qt not a language code
gettext: poqm/es/phononsettings_qt.po: qt not a language code
gettext: poqm/et/libphonon_qt.po: qt not a language code
gettext: poqm/et/phononsettings_qt.po: qt not a language code
gettext: poqm/eu/libphonon_qt.po: qt not a language code
gettext: poqm/eu/phononsettings_qt.po: qt not a language code
gettext: poqm/fa/libphonon_qt.po: qt not a language code
gettext: poqm/fa/phononsettings_qt.po: qt not a language code
gettext: poqm/fi/libphonon_qt.po: qt not a language code
gettext: poqm/fi/phononsettings_qt.po: qt not a language code
gettext: poqm/fr/libphonon_qt.po: qt not a language code
gettext: poqm/fr/phononsettings_qt.po: qt not a language code
gettext: poqm/fy/phononsettings_qt.po: qt not a language code
gettext: poqm/ga/libphonon_qt.po: qt not a language code
gettext: poqm/ga/phononsettings_qt.po: qt not a language code
gettext: poqm/gl/libphonon_qt.po: qt not a language code
gettext: poqm/gl/phononsettings_qt.po: qt not a language code
gettext: poqm/gu/libphonon_qt.po: qt not a language code
gettext: poqm/gu/phononsettings_qt.po: qt not a language code
gettext: poqm/he/libphonon_qt.po: qt not a language code
gettext: poqm/he/phononsettings_qt.po: qt not a language code
gettext: poqm/hi/libphonon_qt.po: qt not a language code
gettext: poqm/hi/phononsettings_qt.po: qt not a language code
gettext: poqm/hne/libphonon_qt.po: qt not a language code
gettext: poqm/hne/phononsettings_qt.po: qt not a language code
gettext: poqm/hr/libphonon_qt.po: qt not a language code
gettext: poqm/hr/phononsettings_qt.po: qt not a language code
gettext: poqm/hsb/libphonon_qt.po: qt not a language code
gettext: poqm/hsb/phononsettings_qt.po: qt not a language code
gettext: poqm/hu/libphonon_qt.po: qt not a language code
gettext: poqm/hu/phononsettings_qt.po: qt not a language code
gettext: poqm/ia/libphonon_qt.po: qt not a language code
gettext: poqm/ia/phononsettings_qt.po: qt not a language code
gettext: poqm/id/libphonon_qt.po: qt not a language code
gettext: poqm/id/phononsettings_qt.po: qt not a language code
gettext: poqm/is/libphonon_qt.po: qt not a language code
gettext: poqm/is/phononsettings_qt.po: qt not a language code
gettext: poqm/it/libphonon_qt.po: qt not a language code
gettext: poqm/it/phononsettings_qt.po: qt not a language code
gettext: poqm/ja/libphonon_qt.po: qt not a language code
gettext: poqm/ja/phononsettings_qt.po: qt not a language code
gettext: poqm/ka/libphonon_qt.po: qt not a language code
gettext: poqm/ka/phononsettings_qt.po: qt not a language code
gettext: poqm/kk/libphonon_qt.po: qt not a language code
gettext: poqm/kk/phononsettings_qt.po: qt not a language code
gettext: poqm/km/libphonon_qt.po: qt not a language code
gettext: poqm/km/phononsettings_qt.po: qt not a language code
gettext: poqm/kn/phononsettings_qt.po: qt not a language code
gettext: poqm/ko/libphonon_qt.po: qt not a language code
gettext: poqm/ko/phononsettings_qt.po: qt not a language code
gettext: poqm/ku/libphonon_qt.po: qt not a language code
gettext: poqm/ku/phononsettings_qt.po: qt not a language code
gettext: poqm/lt/libphonon_qt.po: qt not a language code
gettext: poqm/lt/phononsettings_qt.po: qt not a language code
gettext: poqm/lv/libphonon_qt.po: qt not a language code
gettext: poqm/lv/phononsettings_qt.po: qt not a language code
gettext: poqm/mai/libphonon_qt.po: qt not a language code
gettext: poqm/mai/phononsettings_qt.po: qt not a language code
gettext: poqm/mk/libphonon_qt.po: qt not a language code
gettext: poqm/mk/phononsettings_qt.po: qt not a language code
gettext: poqm/ml/libphonon_qt.po: qt not a language code
gettext: poqm/ml/phononsettings_qt.po: qt not a language code
gettext: poqm/mr/libphonon_qt.po: qt not a language code
gettext: poqm/mr/phononsettings_qt.po: qt not a language code
gettext: poqm/ms/phononsettings_qt.po: qt not a language code
gettext: poqm/nb/libphonon_qt.po: qt not a language code
gettext: poqm/nb/phononsettings_qt.po: qt not a language code
gettext: poqm/nds/libphonon_qt.po: qt not a language code
gettext: poqm/nds/phononsettings_qt.po: qt not a language code
gettext: poqm/ne/libphonon_qt.po: qt not a language code
gettext: poqm/ne/phononsettings_qt.po: qt not a language code
gettext: poqm/nl/libphonon_qt.po: qt not a language code
gettext: poqm/nl/phononsettings_qt.po: qt not a language code
gettext: poqm/nn/libphonon_qt.po: qt not a language code
gettext: poqm/nn/phononsettings_qt.po: qt not a language code
gettext: poqm/oc/libphonon_qt.po: qt not a language code
gettext: poqm/oc/phononsettings_qt.po: qt not a language code
gettext: poqm/or/phononsettings_qt.po: qt not a language code
gettext: poqm/pa/libphonon_qt.po: qt not a language code
gettext: poqm/pa/phononsettings_qt.po: qt not a language code
gettext: poqm/pl/libphonon_qt.po: qt not a language code
gettext: poqm/pl/phononsettings_qt.po: qt not a language code
gettext: poqm/pt/libphonon_qt.po: qt not a language code
gettext: poqm/pt/phononsettings_qt.po: qt not a language code
gettext: poqm/pt_BR/libphonon_qt.po: qt not a language code
gettext: poqm/pt_BR/phononsettings_qt.po: qt not a language code
gettext: poqm/ro/libphonon_qt.po: qt not a language code
gettext: poqm/ro/phononsettings_qt.po: qt not a language code
gettext: poqm/ru/libphonon_qt.po: qt not a language code
gettext: poqm/ru/phononsettings_qt.po: qt not a language code
gettext: poqm/se/libphonon_qt.po: qt not a language code
gettext: poqm/se/phononsettings_qt.po: qt not a language code
gettext: poqm/si/phononsettings_qt.po: qt not a language code
gettext: poqm/sk/libphonon_qt.po: qt not a language code
gettext: poqm/sk/phononsettings_qt.po: qt not a language code
gettext: poqm/sl/libphonon_qt.po: qt not a language code
gettext: poqm/sl/phononsettings_qt.po: qt not a language code
gettext: poqm/sq/libphonon_qt.po: qt not a language code
gettext: poqm/sq/phononsettings_qt.po: qt not a language code
gettext: poqm/sr/libphonon_qt.po: qt not a language code
gettext: poqm/sr/phononsettings_qt.po: qt not a language code
gettext: poqm/sr@ijekavian/libphonon_qt.po: qt not a language code
gettext: poqm/sr@ijekavian/phononsettings_qt.po: qt not a language code
gettext: poqm/sr@ijekavianlatin/libphonon_qt.po: qt not a language code
gettext: poqm/sr@ijekavianlatin/phononsettings_qt.po: qt not a language code
gettext: poqm/sr@latin/libphonon_qt.po: qt not a language code
gettext: poqm/sr@latin/phononsettings_qt.po: qt not a language code
gettext: poqm/sv/libphonon_qt.po: qt not a language code
gettext: poqm/sv/phononsettings_qt.po: qt not a language code
gettext: poqm/ta/libphonon_qt.po: qt not a language code
gettext: poqm/ta/phononsettings_qt.po: qt not a language code
gettext: poqm/te/phononsettings_qt.po: qt not a language code
gettext: poqm/tg/phononsettings_qt.po: qt not a language code
gettext: poqm/th/libphonon_qt.po: qt not a language code
gettext: poqm/th/phononsettings_qt.po: qt not a language code
gettext: poqm/tr/libphonon_qt.po: qt not a language code
gettext: poqm/tr/phononsettings_qt.po: qt not a language code
gettext: poqm/ug/libphonon_qt.po: qt not a language code
gettext: poqm/ug/phononsettings_qt.po: qt not a language code
gettext: poqm/uk/libphonon_qt.po: qt not a language code
gettext: poqm/uk/phononsettings_qt.po: qt not a language code
gettext: poqm/vi/libphonon_qt.po: qt not a language code
gettext: poqm/vi/phononsettings_qt.po: qt not a language code
gettext: poqm/wa/libphonon_qt.po: qt not a language code
gettext: poqm/wa/phononsettings_qt.po: qt not a language code
gettext: poqm/zh_CN/libphonon_qt.po: qt not a language code
gettext: poqm/zh_CN/phononsettings_qt.po: qt not a language code
gettext: poqm/zh_TW/libphonon_qt.po: qt not a language code
gettext: poqm/zh_TW/phononsettings_qt.po: qt not a language code
      

Please ask the translator (identified by the Last-Translator field in the PO file), the language team (identified by the Language-Team field) or debian-i18n for a fix.