Just wanted to say that I have often gotten the same message Josh saw when trying to connect to ShadowNet. As Stripes seemed to suggest, an operator of a server will set their own conditions, whether it seems right to someone or not. But the operator of ShadowNet is not too much of a stickler on his own rules. I sometimes am allowed to connect to ShadowNet in spite of my "uncool client"! TheNet, spica.sytes.net used to do much the same, but has been kinder to WinMX lately.
When you connect, check the /motd in server messages for this net. The operator has a rule, "no kanji...try English!" If you try the chat tab and get the list of chatroom for this net, you will find two rooms, both German language! Not too much of a sticklier for his own rules, this operator!