I also expect a lot of customers ISP has been recorded as "co.uk" :) ?
That'll be a site that thinks everywhere works the same as the .com/.net hierarchies...Anyway isn't your IP address a bit old-fashioned? ;)
I'm not surprised a site that thinks everyone is on '.com' is still stuck on the legacy internet..A more important question is... bearing in mind the pledge not to use suppliers that don't provide ipv6, how did you get as far as the checkout procedure? :p
Not buying IPv4 only stuff is not the same as not using not dealing with no IPv6 suppliers.