Hi all...
A question by Saab Dastard prompted me to look at the state of Norton Personal Firewall, and I could not see the little globe. I opened Norton, and could not enable the firewall. I did a search round Symantec site (a challenge in itself) and it came up with some register to change. I changed it, rebooted, got me globe back, and the secure sites are back too.
If the icons of proggies in use had not been 'hidden' I would have noticed the green thing missing and posibly solved it earlier.
I sincerly thank all who have bothered to give input however, and of course, the reason for the firewall getting turned off still remains a mystery.