Damn dude =) I'm system administrator of small commercial bank, here in Moscow =) Of course I know how to set router and how to use firewall =)
I'm in the provider's subnet and I have "gray" IP address, it means that I behind provider's NAT either. So, if winmx need real IP to listen incoming connections thats understandable.
I didnt opened port range, just set redirect from WAN to my server in LAN, ports that I marked higher in this post.
I should know how winmx server connects to the client, maybe it remembers clients address and then needs to send commands to open ports, and thats why he cant see me behind provider's NAT, so I need to set in winmx that I cant listen incoming TCP and UDP. If so, I'll put that settings back, so people could UL from me.
Sry for maybe bad english, not my primary language =)