xbox live help

Hey guys I just bought xbox live and a d-link 604 router. I bought the router because I couldn't get the xbox live to reconize my ip address and all of the other info.
So I got the router, hooked it up to the wan DSL line and I pluged the ethernet cable into the xbox. It then reconizes my ip address all of the info it didn't before and im just about to jump up for joy when it says ... DNS not resloved.
At the time I just had 1 com being used to connected to my xbox. So I hooked up com2 to my computer and set it up and the same problem seems to be happening on my xbox. I even put on DMZ mode and tried taking down the firewalls but I think there iss something I am missing! It's really starting to get to me because I spent more then 150. The thing im starting to wounder about is that On my computer when I plug the wire in from my d-link router to my computer it says connected but... If i click on IE or aim it says I am not online. Can any one help me!?
So I got the router, hooked it up to the wan DSL line and I pluged the ethernet cable into the xbox. It then reconizes my ip address all of the info it didn't before and im just about to jump up for joy when it says ... DNS not resloved.
At the time I just had 1 com being used to connected to my xbox. So I hooked up com2 to my computer and set it up and the same problem seems to be happening on my xbox. I even put on DMZ mode and tried taking down the firewalls but I think there iss something I am missing! It's really starting to get to me because I spent more then 150. The thing im starting to wounder about is that On my computer when I plug the wire in from my d-link router to my computer it says connected but... If i click on IE or aim it says I am not online. Can any one help me!?