hey horst,
hmm, that's strange. I just searched for this text (as I'm not using badges at my site) and the result was that it's coming from this string: COM_EASYSOCIAL_BADGES_NEWBIE_DESC
going from here this string is also available in the german file, around line 3048:
/administrator/language/de-DE/de-DE.com_easysocial.ini:
3048: COM_EASYSOCIAL_BADGES_NEWBIE_DESC="Glückwunsch zur Registrierung auf der Seite"
to take it one more level I also double checked transifex and there it is as well as you can see in my screenshot:
http://screencast.com/t/v1qS47LRpMt
can you try to load the language files again from your easysocial backend and then check if the string is still missing in your file? if so, as said, please provide us with your details so that we can check on it.