I hope hamphork's suggestion works for you. I am aware there's a number of ISP's in S.A. who shape or block p2p programs. I hope that doesn't apply to yours.

If it doesn't work, then try to find out the brand & model of your connection device. (A router is usually a modem with options to connect other computers to it also. It acts as a type of hub of a network connecting them to the internet.)

What you can try is going to LW's menu bar, Tools>Options>Advanced>Firewalls & change the listening port to one between 49152 - 65535. Try 64049 & then close & re-open LW.