Problems Loading COD4 Online Xbox360

Hey guys I'm new to this site and I am having a bit of a problem trying to connect to COD4. I am able to sign into Xbox Live then I join the multiplayer icon, once there i click find game. It finds a game but very slowly then once it finds a game, I wait atleast 5 minutes before it actualy joins the shooting part. It stays in the loading screen but I can still hear everyone speak and they can hear me. I think it may have to do with me lagging but I get 4 green bars when I join the game, if it doesnt finish before I join. I've tried calling my ISP(internet service provider) and they couldn't help saying that my connection was perfect. I've called xbox and they told me to contact my ISP because xbox didn't know what they were talking about.. telling me to unsecure my network or switch service providers... morons... I've haven't had these problems before. This all started when rogers first shut down my internet. Since then i've secured my network. Any help would be great guys!

hmmm....

you sure ur CoD disk is not scratched anywhere ?

Look into your NAT settings, make sure they are open or moderate, if it's set to strict you will be waiting a very long time to get into COD4 games. Adjusting some settings on your router should do the trick, if you say what router you have I'm sure someone will be able to help, I'm not very good on giving advice on tweaking settings on routers but I'm sure some people here know what to do.

You can test your 360 by going to the last blade on your dashboard and clicking network settings/ test xbox live connection, note what it says next to NAT, if it's open or moderate then I don't know what your problem could be,