Membership Plugin - Initial Setup Issue


I've setup Membership on a local install of latest WP/BP.

What I'm looking to do is have three user types - public users, clients, and staff. I've tried setting them up to restrict content by category, by post and by page, and am having no luck at all so far.

I've reinstalled with a clean DB and starting again, in an attempt to get this thing working. Here's what I've done:

* Added a new User Level - "Public User" - which had a negative rule to block users of this level from all categories of posts
* Added a new subscription - "Public User" - to give this User Level for free and for indefinite time
* Applied "Public User" to be the "Stranger" setting, and also applied it to a user

This should block all blog posts from both strangers, and this user, but both an un-logged-in visitor and the registered user can access the blog listing and single page of a post without issue.

Any help greatly appreciated!