I was seeing that too for port 80 but when the other machine here was shut down, then 80 showed as stealth. I tracked it down to a game program at Yahoo that when my friend is playing, port 80 is opened in the router. For me, port 113 always shows as closed but not stealthed no matter what I do but when I look it up, it seems it’s nothing to worry about. I think one of my games uses it for authentication of my account, probably World of Warcraft.
I had never ran any test of this type. I ran the all service ports 0 thru 1055. All were shown closed but not stealth. Is this a problem if so how would I proceed to fix it. Is there a setting in the firewall? . Thanks