1. Make sure you have freeboot and Dashlaunch properly installed
2. Make sure you have the Ping Patch
3. Make sure you have forwarded port 30000 correctly
4. Mae sure you are using the latest title update for whatever game you are trying to play
5. Make sure Xlink can actually see your mac address. To test, using the interface (not the web browser), click join game in your system link enabled game, then in xlink click the magnifying glass, then switch view to see if your mac address is there.
6. Keep in mind, only clients need the patch/jtag but the host does not (i have tested this).