Multi site settings

Ok here is what I want to accomplish. I want a user to have to sign up to use the site. Then I want only logged in users to be able to register for a site.

I checked the box for logged in users can register for a site but then no user can sign up for the site. So I went back and changed it to both site and users can register. However then you can only register for a sign when you sign up as a regular user. So if I am already a user I have no way to sign up for a site.

What have I set wrong?

Thanks for your help!