After installing CAV I noticed in the XP event log the following:
Error: Timeout (30000 milliseconds) waiting for a transaction response from the NVSvc service.
Also:
Error: The IPSEC Services service terminated with the following error:
An invalid argument was supplied.
This has been confirmed as a bug, after uninstalling CAV the errors go away. This has been tested on a new installation of XP SP2 on 2 PC’s with all the updates installed.
Hello,
Comodo Antivirus has had some conflicting issues with some programs, however this is the first I have heard about Nvidia drivers, I would suggest for you to forward this to support by submitting a ticket to
Also CAVS 2 Beta is being released soon.
Have you tried adding the “NVSvc service” as an exclude in the on-access and on-demand scanner options?
Ewen 
I have installed and uninstalled the beta now the ipsec service don’t start anymore:
Error: The IPSEC Services service terminated with the following error:
An invalid argument was supplied.
Any solutions for this?