HTTPS Facebook API requirements

First problem:

For my main hosting I have standard SSL.
I added multiple other domains through WPMU and installed "SSL for subdomains" as well as "HTTPS for Wordpress" plugins. (These plugins require forcing SSL_LOGIN->true in wp-config)

But when I go to https://addedsite.mainsite.com I get the
"you tried to access addedsite.mainsite.com" but instead you actually reached a server identifying itself as mainsite.com. This may be caused by a misconfiguration on the server or by something more serious. An attacker on your network could be trying to get you to visit a fake (and potentially harmful) version of mainsite.com. You should not proceed."

Second Problem:
I use a program that works with the Facebook API requiring HTTPS secure pages.

I am basically trying to provide SSL for my MU added sites in a way that I could integrate each of them into Facebook.

Does anyone know of a way to provide SSL across pages of WPMU added sites to work with facebooks api requirements?