如何部署ASP.net自定义MembershipProvider？

I've written a custom MembershipProvider that uses a custom database schema for storing the members, but I am having trouble figuring out how to deploy the provider. My target server is running IIS7, and I am able to navigate to a dialog for a adding a .NET User Provider, but instead of allowing me to select the assembly containing the provider & then the class, it provides a drop-down with a couple of MS written providers. I've written a custom MembershipProvider that u