Trying to get Multi-Domains to work with Domain Mapping

Hello,

We've successfully mapped carnivalcities.org to carnaval.bz/carnivalcities

Trying to use Domain Mapping in conjunction with Multi-Domains, which as I understand it should be possible?

However, when I go to add a new site from the network admin dashboard (carnaval.bz/wp-admin/network), and try to create carnivalcities.org/test I simply get redirected to the network admin dashboard.

I've installed the latest version of multi-domains (1.1.6) and domain mapping (3.0.7) and followed the installation instructions.

We are running WordPress 3.2.1 at present - could that be an issue?

Thanks!