If you can't dl from firewalled hosts, it is because you're behind a firewall yourself! Limewire got this wonderful 'push-request' message to allow non-firewalled hosts to dl from firewalled hosts. But it's impossible to establish a connection between two firewalled hosts. So, if you wanna block firewalled users, just delete c:/program files/limewire/ and you're done

Are u sure firewalled users are downloading from you?