xbox live: fail at dns?

I have done the ipconfig/all thing and entered the correct dns settings on the xbox but it still doesnt work. I've tried everything on the official xbox website and 10+ other forums for months now. plz help.

btw i have a wireless connection with a 2wire router

What router is it?

Make sure your MAC address is added to your routers accepted MAC address list.

Also always select options for "automatic" IP address as well as others.