I have a Linksys 4 port wired router, Win XP, cable. I have not played the game in months, when I refresh the list for a list of servers it says getting information for 512 servers, but no information is displayed. When I disconnect the router and plug the cable directly into the computer I have no problem. This never happened before and all my other games, email Internet access work normally.
Your router might have ping reply disabled. You might want to enable this to make sure you get the information correctly.