http://list.genealogy.net/mailman/archiv/sachsen-anhalt-l/2004-01/msg00036.html http://list.genealogy.net/mailman/archiv/mecklenburg-l/2003-03/msg00119.html Seems like a noble German family dating back from the Late Medieval Ages from a family of knights. The links are in German, so maybe Andy can help you from here. I'm too tired right now, i'm sorry.
Droga seems to be Polish too. It is a Polish surname, but Walloon? Are you sure about that? Apart from not appearing French or Flemish, I only hit sites about drugs at Google.