Remy said:You have your firewall blocking incoming traffic from your LAN? I can understand blocking traffic from the outside, were it getting past your Airport for whatever reason...but blocking on your LAN seems overly paranoid.
You should set the OS X Firewall (System Preferences -> Security) to Allow all incoming connections, and at the Airport level you should not forward any ports.
Oh? How do I know my Airport station is doing the protecting then?