If you have a child (my son) who has a 360 Xbox live... it will hose the connection even if he is not playing online... make sure they disconnect the network cable when not online...
I'm thinking of ordering another high speed connection to be used exclusively by me ONLY for online gaming...
I believe this will solve the ultimate problem of multiple users hosing our connection...
Just remember that insanity is hereditary... you get it from your children!!!