Hmm ok, I've installed gnome now and it works with the normal X.
When I start Xgl I see the grey startscreen and my cursor.
It doesn't really freeze, i can still move my mouse around but it doesn't continue either.
As I posted before, when I try to Xgl -configure (or X -configure) it crashes with the above errors, here is the logfile:
http://nanobin.nanosouffle.net/1995
I have the fglrx drivers installed but there is no Xorg.conf file in my /etc/X11...
Thanks for your time!