When one https site calls out to another and they both live on the same server there may be a gremlin.

I'm not sure how to beat this problem just yet. If you have a web site that is a "client" that reaches out the "core" web site at an https address and the client is hosted locally at your laptop or whatever, you may experience trouble if you just set up the client at the server holding the core site and expect the two to cross talk there, and really that is true even if the client isn't https. Without any variables seeming to change, the client just won't be able to talk to the https address and the https address must become an http address to counter the problem. If you're hitting the client via https in this scenario the client will then start throwing JavaScript errors which complain of the mishmash of http and https and you'll end up dropping the https for the client too. I'm not sure what to do about this yet. It is one-off wackiness as far as configurations go so maybe I don't have to think about it too hard. Whatever. If the two things were meant to live in the same environment you'd probably just have one web site.