Links in pages of "Mapped Domain" point to incorrect sibling "Mapped Domain"

I've added some mapped domains so that I now have:

http://bookings.mydomain.com
http://bookings-toyota.mydomain.com
http://bookings-ford.mydomain.com
http://bookings-nissan.mydomain.com

My problem:
The links (like the "Hello World" for instance) inside the mapped domains all point to the Toyota domain. Except for the vanilla http://bookings.mydomain.com, which correctly points to itself.

It's strange because its not the first alphabetically, not is it the first one I've added. I also don' t think it the first one to be resolved via DNS. So not sure why its picking the toyota.

How I get the link to "Hello World" in the Nissan version of the site to point to:
http://bookings-nissan.mydomain.com/Hello-World ?

Any help would be greatly appreciated!
Stephan