I didn't create the userfriendly node name "Test_Link" and hoped, that the system would generate automatically "Test_Link" from the node name "Test Link".   
Thus http://debategraph.org/Test_Link didn't work as expected. Instead of this, it produced : 
 
 
 Sorry access to the Debategraph map you selected failed
   cu -- fridemar 2012-03-16 23:49:47 CET