This worked for me so maybe it will work for others

I was having the same problem and couldn't figure out how to open up the ports listed on the MS link.
http://support.microsoft.com/default.aspx?scid=kb;EN-US;Q159031

I have a D-links 604 4 port router. Under the advanced tabs there is a area for me to open ports. Name it Web server, type in 192.168.0.1 for the router IP and select the 4 port numbers  (80, 443, 6667, 28800-29100)

Name: Web Server
Private IP: 192.168.0.25
Protocol Type: TCP
Private Port: 80
Public Port: 80
Schedule: always

Now once you do this for all of the ports open up your command prompt, type ping zone.msn.com and if you get a reply you should be good to go

bumbing this back to the top for a friend of mine