@Unbelievable perhaps you could make a change (date?) to the front page of the site and we could see whether that propagates - or we are looking at a cached page?
@Unbelievable Yes - are you Noel?
yes i am
@Unbelievable I use WordPress too for my sites eg Portobello Central I have to "purge from Varnish" and "purge the performance cache" or else some stuff doesn't appear.
As you can see I'm not an expert!
I can access the site using Google or OpenDNS but not BT DNS. Might be worth getting your hosting company to talk to BT to find out why their DNS servers aren't getting updated.
I'm swapping by setting manual DNS config for various servers in the Ethernet adapter and using BT servers on Wifi
Further testing reveals that if I have IPv6 enabled I get a 404 but if I disable it, I can access the site using any DNS server.