Hm,
I figured out if I don't use these two entries:
#RewriteCond %{HTTP_HOST} ^koehler\.uni\.cc [nc]
#RewriteRule (.*) http://www.koehler.uni.cc/$1 [R=301,L]
#RewriteCond %{HTTP_HOST} ^oubsu\.org [nc]
#RewriteRule (.*) http://www.oubsu.org/$1 [R=301,L]
It works fine without those.....
Any idea how to make both work??