Xbox 360 Network Problems

[1993draken]

Okay I will explain to you all of my hardware and how it is set up

I have a cable modem supplied by my local isp
I have an Apple AirPort Extreme Wireless Router
I have 1 wired desktop and I have 1 wireless computer
My xbox gets xbox live by sharing connection with my laptop

Okay now what is going on here is that my xbox will connect to xbox live but randomly disconnects. When I start up my console and try to log in everytime it will say that something is wrong with your network connection and that i should test it. I do the test and it says that there is no problems and that xbox live is up and running. After this I am able to sign in with no problems. Now when i am playing Halo 3 or any other game for that matter I will get to about halfway through before it goes to the connecting page where is shows all of the players and there amount of kills and connection qualities and whatnot. It will say that I have piss poor connection quality and I will not be able to hear what the other players are saying. Shortly after this I am brought to the lobby of the game and the xbox interface will say disconnected from xbox live. I will go into the xbox guide and click on connect to xbox live and I will have to test the connection again like I always do and it will say that there are no problems with the connection again but I will start playing again and the same thing happens.

Now on my apple router I do have all of the ports forwarded that are necessary according to xbox live customer support. My laptop also is connected wirelessly at about 80% in wireless n 5Ghz mode. I do not know what is going on with this and I just got my xbox live gold card and I am very upset that i can not even play... Somebody please HELP!!!