Hoping for an answer!

Ok, 3 weeks ago, I ditched RoadRunner highspeed internet, to downgrade to At&t Dsl.. So the guy comes.. Installs it and whatnot and hooks it up to the Belkin G router.. Which is the same router we used for RoadRunner cable internet.. Never were there Any problems whatsoever..

Now.. I have a Playstation 3..I play on the internet.. Alot on it, especially Call of Duty 4.. On the first match I played, I get the Internet Disconnected sign.. Oh well, I thought, and i just joined another.. About 10 minutes later i get the same sign.. WTF? So for the past 3 weeks, I have been getting disconnected from the internet for a few seconds, every 10 minutes..

Well, you might say.. Whats the problem? Believe it or not.. I play many online games that require a constant connection..Such as Starcraft, WOW, and RS... Those all log you out of your game if you lose connection.. So every 10 minutes, I'm logged out of my games, which as you might imagine leads to many headaches and deaths in those games.. I am tired of it!

I have called AT&T, and they told me the problem was not with the modem, but with the router.. So I call Belkin.. They try to help with step by steps, and yet I still get the same problem.. The internet is wireless btw... I have 2 laptops and a PC.. Both lose connection at the same time for a few seconds.. As well as the PS3..

I have disconnected Phone wires as well, still the same, I have reset the modem and router.. Still the same.. I have moved the modem and router 4 feet from the nearest electronic.. Still the same..

So I am asking you.. Please help!?