ActiveDirectoryMembershipProvider - How to Set Trust Level? How to Fix Unable to establish secure connection with the server Error? Or Object reference not set to an instance of an object Error?

I've spent a week plus searching link afte link on people using the ActiveDirectoryMembershipProvider.
Grabbing Roles (Groups) from AD no problem, but actually getting User Information with Membership.GetUser? Fails everytime.
In the end I ended up followng the steps in this blog post (http://blogbybob.com/archive/2007/03/09/active-directory-membership-and-roles-in-asp-net-2-0.aspx )
Problem is with:
<add name="ADMembershipProvider" applicationName=" Go to the complete details ...