There's a much better way to get opennap servers, and that's with
http://www.napigator.com/ It's updated in real time.
For WinMX2 (don't know about 3) you should use NapMX to automatically update your OpenNAP list, so you don't go crosseyed typing in IP addresses,
http://napmx.darkservers.net/
I myself run a server on the DarkServers network.