Getting disconnected with router use

[dmaksymyshyn]

I am using a cable modem (road runner) and my router has two computers connected. After a random amount of time, the modem fails, I lose the connection, have to reboot the modem, and reconnect. Very annoying. When I remove the router and connect either one of the computers separately, everything is fine, no issues with connectivity. This all started about a week ago, prior to which I never had any problems. I have updated my router software (4 port Belkin router - not wireless one), but still looking for help? Settings on my computers?
Both computers are running on Windows XP.

[bAdWaYz]

When the connection fails do you see the lights on the modem change? How is the modem connected to the router?

[dmaksymyshyn]

Abosolutely no lights on the modem change when it fails. When it has failed, I have called my ISP, and they have said all is well, and the connection from them to the modem is all well. I believe that somewhere between the router and the computers is the problem. Currently, everything is ligthed up, the LINK light is flashing (which it always has), and I have the modem connected to the router using a standard network cable. Modem to router, router to two computers..that is all.
Ideas?