router and dsl modem Problem! HELP!!!!

ok here is my problem. i have a one port Linksys router hook to my dsl modem. The problem im haveing is that i get disconnected every 2 min then reconnect. my pings go from 70 to 20,000. So i updated the firmware to the latest ver. Now its every min. When i take the router out and hook my computer to the modem everything is fine, no disconnect or reconnect. So i thought it might be the modem. A friend told me that SWB told him to put the modem away from and power outlets. So i put it on the floor. it still does it. Now i went with a different router, a net gear. it does the same thing. When i boot up i get on the net just fine. Then it starts again. Now with the new router its every min. Chould it be the modem doing that? Or maybe the SWB people upgraded some thing and thats what is causing it. Or chould it be a setting in the router. It seems I'm left with putting 2 network cards in a computer and using it that way. I would like to keep my network up with the routers instead of using the computer as a router. Any ideas. This is really fustrating.