Xbox Live Kicks Me off Every 5 Minutes. I Have Everything Set Up Right?

i just got halo reach and have been trying to play online but only to my surprise it doesnt work because my internet is retarded. i've had this problem before and opened ports and made a static ip address and it worked. but now it deosnt want to work. i got a new modem from motorola and then it started to not work, but i went to the router page and everything is the same. still open ports and DMZ settings. it seems like i can connect to xbox live using a automatic setting on my xbox but i get kicked off every 5 minutes. however if i click on sign into xbox live i will sign back in. however when i do the manual settings it says the xbox is connect to the internet but can not connect to xbox live. SOMEONE PLEASE HELP

Suggestion:

Do you have the 4 GB Slim? An issue with playing online with it has come up, and fix is being developed right now.

Tagged as: halo reach kicks me off every 5 minutes, i get kicked off xbox live every 5 mins, xbox live kicking me off