Looking at my firewall in YAST> additional services
6881:6999 TCP
6881:6999 UDP
In the router I have this same port range setup. I just set it by the advice given by D-link. I think Azureus claims 6881 by itself is enough. It probably is.
I can't remember doing anything else to get this running.
If you have only one machine on that router your already pretty well protected. The firewall is more like a failsafe.
Maybe by ^bumping^ this thread someones memory will be jogged