internet access and security

[Fieldcrest]

I recently moved and got internet access through Comcast Cable. They provide the modem and the service. I have XP with CounterSpy and PC-Cillin. One day one when it was installed everything worked fine. Then on day two the internet access was no longer there. I could tell the modem was working fine and that my system was ok. When I called the customer service people at Comcast they said that I needed to switch off and on my modem because of some new security feature whereby they are periodically switching IP addresses. I asked why that would disconnect me and they said it was probably my various anti-virus programs and suggested switching those off. That didn't seem like a particularly safe thing to do and to be honest I didn't really understand what they were saying. So my questions:

1. Does anyone know what this periodic bouncing around of IP address is about?
2. Is there something short of switching off my security or switching my modem on and off that I can do?

Any thoughts would be much appreciated.

[Ob1]

maybe the tech meant you are on there service that is set to dhcp as far as bouncing the ip's around. ive never heard of that from comcast
if your ip addresses are switching then you will have to reset the modem and either release and renew for your new ip address or restart your pc if it doesnt change it for you automatically.

make sure your not running two software firewalls. since you are running win xp make sure you turn off the xp firewall and only run pc chillin.

[Fieldcrest]

Thanks for your guidance. Only one firewall running.