Well, that might explain it. So you just use the "UDP via Tracker" option? Weird, it couldn't find any trackers when I tried that... 
It should say "2 Trackers Found" underneath the socket stuff ("current socket is +0...blah blah blah)
If you're not finding any trackers, you may need to forward port 9424 (I think that's right), check if your router--if you used one--doesn't have any NAT issues or UDP problems, etc...
<offtopic>
Hope you have a great vacation Dark Hunter. Heh, I'm gonna be at vacation this weekend as well (skiing
).
</offtopic>
Ummm guys, the default port for the tracker is
28342. Change it if it isn't that number.
All the guys I've been playing online using the Tracker, are using this port number.
If you don't see any games listed, chances are there is just no one playing at that moment, or the router/ modem you are using needs the port forwarded.
For my router its setup is the following:

If you need help setting up your port forwarding for your router?
Go
here and click on the router that you have.
Once you are done.
Get someone to host a game.
Fire up D2X-XL.



Select tracker. Type in the port number ( default is 28342 ), and wait for the game to pop up on the list.

Good luck and see ya in the mines!
