Mika,
I have 2,3,4 checked, but the morning after it seems to be working. I think the DNS finally updated properly, and I figured out the difference between the sub-domain sites, and the way that the domain-mapping plugin worked.
I realized that you put the subsiteb.mainsite.com in the Sites listing and then put the ID, which you can see hovering over the subsiteb like, in the domains plugin with the subsiteb.com information.
Thanks! It Works!
Greg
