Did you check the Xbox website to see if your new router is Xbox compatible?
Are you talking about using a hub instead of a router. That would just cost you a lot of $$$ since you would then have to pay for more IP addresses. A hub ran between your router and your Xbox will do nothing since it has to go through your router anyway and that does not seem to work as is.
First thing to do is check and see if your router is compatible with the Xbox. Some routers need a little finessing to get them to work with the Xbox.
http://www.xbox.com/en-gb/live/start...aq/routers.htm