check your pm please
i send some further information where. i edited most of the stuff already.
I don't see any more messages. I see four messages, the one telling me the URL, two talking about activating my account, and one talking about the locales.
In the one talking about the locale, you are referring to the gravatar plugin only.
You have not made german translations for all of the plugins on your site. My theory is that one of the other plugin's English translation is overwriting your gravator german translation. you say that the gravatar english translation is not conflicting with the german, and I agree.
Try changing all plugins "configuration" label to something else, and you will see it change, I'll bet.