WCG200 Cable modem Router Keeps rebooting, dropping network

Hi,

Webroot and Norton discovered Tibbs Dialer dialer trojan and erradicated it.  
It seems however that ever since, my cable modem WCG200 Wireless G Cable modem 4-Port Router is rebooting very frequently (every 30 Minutes)
This is my second one in five months.  

I've called comcast, and they claim there is no network problem from their end.  

All the ports are filled with VOIP, Workstation, Printer, webServer - and on the wireless side, a laptop
I've taken individual items off the network, powered down the router and reset it.  

Nothing has worked thus far..  

I want to upgrade and get a high end cable modem that can utilie the 1000 Gigbit ethernet cards I just bought.  
First, can anyone give me advice about what may be causing this router to fail and how I can troubleshoot fix it?  

Thanks..