I'd have posted this on the Solved Issues forum but that's closed to new threads ...
The solution is to disable automatic updates for the product. That means that I can only process updates manually, which is risky.
The problem was ...
The wireless network connection & Internet Connection Sharing (ICS) from other PCs was zapped to a fictious 168.x.x.x IP address which I researched to mean "there was a problem" & ICS settings were reset on the provider PC to disallow ICS.
This happened randomly (maybe hours OK maybe less than a minute OK). This also happened whenever any of the networked PCs was rebooted.
I tried static IP addresses, no joy. I tried different wireless dongles, no joy. I tried relaxing firewall permissions for networked PCs, no joy.
Setup:- Broadband modem connected only to the main PC. Main PC is set up to act as a router for other PCs on the wireless network (for private reasons I will not change this, nor should I have to).
The solution has worked now for 24 hours without failure.
Ray (Addendum:- this problem has caused hours of work, money spent unnecessarily for new equipment, lost effort, lost online relationships, many many angry moments and a serious family row. I have used McAfee since January 1998 but this issue is making me reconsider my loyalty.)
Product details:- Security Center Version: 9.3 Build 9.3.162