Marius, I moved your question to this thread to keep the clan reg as clean as possible.
The Problem ist that the tracker is challenging the server in a never ending loop. The first protocol which the server responses is set.
A solution could be to setup a single server facade and forwaring it to your real gameserver. :
http://equalone.freeunix.net/If you config it to responses the 2.60B protocol it will appear twice within SL (use the next port to the one the real gameserver uses)
If you`re not able to create such a facade (maybe the hoster will deny it) , don`t hesitate to contact me for a solution.
Kind regards
Schnoog