Virus scanners are usually just virus scanners but, I have heard of them causing problems before. As to whether yours has a firewall... you'll need to check all its options.

As a general rule most usb modems/routers don't use internal firewalls. But if yours does then you'll find out if you can change such options such as which ports are open. See: http://www.portforward.com/sagem/Liv...forwarding.htm which is not your model but it's the best I could find at short notice. Your manual might explain more. IF you need to forward a port you need to go thru these processes (very important): 1. Set up a static ip. 2. Forward a port; LW uses port 6346 by default. 3. Within LW set up the manual port forward: Force IP/Manual port forward instructions & sample image AND 2 posts after that.