This bug report is a condensed version of forum: http://forums.atlassian.com/thread.jspa?forumID=96&threadID=14948

On my dashboard it says "Vor kurzem Aktualisiert" instead of "Recently Updated", everything else seems to be in English.

This problem was solved after I deleted de_DE-1.0.jar but this seems to be a bug, doesn't it?

My guess is it's a missing property in the specific local you selected for english, so it defaulted to your computer's locale(Germany), which seemed to have one specified.