I've installed the mu domain mapping, but i can't make it work. I have two different domains, one is point to the other domain (set up at mediatemple to point to the other domain's folder). That's working.
But when i use wordpress (not a simple php test), it's redirect to the primary domain. (I added the domain, set up cname primary.com.)
So: www.secondary.com redirects to www.primary.com/secondary.
P.s.: Using lastest WP 3.6; from a domain/server dummy