strange broadband problem--connection periodically lost, rebooting restores it

[Xede]

My broadband internet connection periodically dies, especially if I haven't been actively using it for a while (after roughly 15 to 30 minutes, though sometimes less). When I lose the connection, the cable modem's lights still indicate that it is fine. Power cycling the modem doesn't fix the problem, but rebooting the computer always restores the connection.

I have Comcast broadband, a new Toshiba cable modem, and the computer is running XP and is the same computer that ran for months with no broadband problems at a previous address before I moved. I'm not using a router and there are no other computers on the connection.

I called Comcast tech support when the connection died again earlier today. The tech said he was getting unusually high (3000) pings for the cable modem and could not ping the computer at all. After I rebooted the computer, the connection was restored as always, and he said the pings for the computer and the modem were back to normal, in the 50s.

He was at a loss at what was causing the problem and told me to keep a log of the problem and call back in a week, and he would ask around and leave notes in my account if he found an answer.

Any ideas on what's causing this problem?

Thanks a lot.

 

[Uconn411]

Have you tried a different card? I have Comcast as well, and for some reason, it didn't like my Linksys NIC. Switched to 3Com and problem went away. Also, in the device manager, make sure that the NIC isn't shut off to reduce power consumption.