Shared SSL and user login

I installed the plugin, but it isn’t doing what I need. I’d like to use my hosts shared SSL certificate to secure the log in page only. When I do this, I’m logged in on the shared SSL domain, but not logged in on the not secure part of the site. I’m trying to secure certain parts of the site to members only.

So when someone logs in through the secure page https://my_ID_on_the_shared_cert.myhost.com they are logged into the site and and can visit any page in as long as they stay in “https://my_ID_on_the_shared_cert.myhost.com/blog/” but if they go to http://myurl.com they are no longer logged in – WordPress has no idea who they are. I’m sure I need to pass the cookie from one domain to the other, or do something like that, but I have no idea what. Can someone please help?

http://wordpress.org/plugins/wordpress-https/