My guess is the problem is your router. The reason you're getting the brick wall is most likely the internal NAT firewall it has. Go to http://www.portforward.com/routers.htm & look for a similar model as yours in the 2nd column from the left under the heading Huawei & follow the directions there carefully. After you click on the model link, look for LimeWire on the list.

Also, if you're using McAffee then make sure it's configured to allow LW full access; (advisable not to have 2 active firewalls b/c they can interfere with each other); Firewall configuration instructions (click on link). And make sure XP firewall is disabled via your control panel.