ok here's the deal. i always used to have a dsl connection running straight through my router (DLINK g604t) to computer and xbox. recently moved house, and now have a cable connection, to through a modem (motorola SB5101) to the router, to a desktop, laptop and xbox. or at least trying to. The computers both connect to the internet (wired) but always need to reset ip addresses each time they are turned on, strange. The xbox has never worked through this configuration, always failing the dns tests. i have tried automatic settings. manually setting ip address and the correct dns servers used, but still always fails at dns tests. tried plugging it straight to the modem as well but the same story. Also the laptop can not get wireless through the router, it only allows local network...no internet through wireless, this has never been a problem in the pass. messy setup i know but any ideas??? thanx

Sounds like your cable provider is blocking some ports. Call their support line. If that isn't the problem, you may need to configure your router to forward certain ports to the devices in question. The cable company support can assist you with this or other router settings to make this work.