The problem is definitely related to the McAfee Anti-virus, as it first showed up on a laptop when visiting a relative, and then subsequently at home with two desktops. Also immediately before I cracked the problem, I checked that there was still no access, uninstalled McAfee & immediately checked again - and that's when everything worked fine again....
As I still have McAfee on the laptop - I've tried again. The page came up with a page not found & then a McAfee pop up showing a 'risky connection' blocked - I looked at more detail & then did a look-up on the IP address to confirm that it was the homepageofthedead.com domain that was the source:-
Attachment 1285
I'm just happy to be able to catch up on the gossip..