Domain Mapping Issue: Domain maps to main blog, not user's subdomain

I recently upgraded to the latest version of Supporter and Domain Mapping plugins. I received a new Support sign-up and the user attempted to map is domain to the server's IP address, which I specified on Super Admin -> Options. I have checked the user's A Record at his Domain Registrar and it is correct. He is attempting to map http://www.haitiphotolibrary.com.

As you can see, his mapped domain is being routed to the main blog site. What am I getting wrong here? What else can I check that might be causing this issue?