Xbox Live Dropping Out

Ok, so I'm running my 360 into a D-link router with a wire, then the router is wired to a moterola modem, just so you know my set up. Every time I use the quick match to join games, namely Gears of War, it loses my connection and I need to reconnect to xbox live.When I reconnect it connects fine, until I try to join a game again, then the same thing will happen. The only time it seems to hold a connection is 25% of the time I play Street Fighter online. Also, it will randomly disconnect at other times to. Does any one know why it keeps disconnecting me? Or better yet, how I could fix it?

Oh, and I tried wiring the xbox straight to the modem and that doesnt seem to work at all, I can't even get a connection that way.
Also, if i run the test connection option, it always works flawlessly.

Thanks!

well man its been a while since i had to deal with this type of problem, but i myself had a similar issue. i had a d link wireless router connect to my original xbox for xbox live from my downstairs computer a few years ago. it worked sometimes, but was not very reliable . it would work then kick me off sometimes. after a while of disconnecting i couldnt take it anymore. it worked when it wanted to. so i went out and got a linksys router at someones advice. ever since then i havent experienced any problems and have had a much smoother experience on xbox live.Now, i dont wanna be that guy that  tells u to go out and spend more of ur hard earned money on another router bc i know it is a pain in the a$$ to have to buy more stuff when u just spent hundreds of dollars on the system itself. so id say get someone u know who has live or is good with routers to come over and look at it. thats the cheap way. all i know is that once i ditched my d link wireless router for a linksys i was set

or maybe gears of war doesnt like you....if thats the case screw gears and get rainbow six vegas.........the real deal in online multiplayer shooters ;). hahaha jm hope i helped u out at all