Thanks for the reply, I think there is a seperate issue as i do have it working in ZOO on another website.
I registered the first domain
fine and the app works in ZOO on that site (I have subsequently tested it).
The second domain
is hosted on the same server with the same IP address. When I tried to register it for an account at are you human it said could not add domain - but then still gave me the keys.
My guess is that the problem is here.
I am planning to test with the same keys I use for the first domain registered and see if that works.