i cannot stay connected for long lenths of time, i test connection and it either days invalid ip address, or theres a problem with DNS on my xbox dashboard whilst my xbox goes offline my computer will not load even the home page, nor connect to msn, but my network places says im connected. ive looked at the connection guide and do not know why its D/C me... any help. i have not got no viruses, i recently scanned..?. i can connect and browse internet but suddenly it will cut me from XBL and not load IE pages so i have to either restart pc and xbox, or keep turning router off which im sure isnt good for the router.

My router is: Bt voyager 210 ASDL router (updated firmware and driver)
when i try and use internet and msn the troubleshooter for msn comes up and says this

Exact Problem: DNS unable to resolve ip address.