I've got site "A": http://site-a.com/ that is the main/

Hi.

I've got site "A":

http://site-a.com/ that is the main/ default site for a WPMU installation with Domain Mapping & Multi-Domains plugin installed.

Domain site-b.com is pointing to the same IP as site-a.com.

http://site-b.com shows up in WPMU as an available domain.

But all requests to http://site-b.com are being sent an HTTP redirect (301) to http://site-a.com.