When LW is open, click Tools->Options & go to Bug report & click for an example. In the window that appears scroll down to the part that says: "Recieved incoming this session". If it says ‘True’ then LW has no problem with firewalls, but if 'False' it does have a prob.

Seriously though you should check YOUR hardware. I only just moved over from dial-up less than 2 weeks ago.

Try restarting your comp. It'll clear a lot of things up.