Membership Cannot Find Reason Why Content Is Not Locked

Hi
I am using the latest version of the plugin

I have a site where I want people to register for free before they can use a form to submit info
http://census.wildlifeact.com

For example this page is locked with a short code <register>
http://census.wildlifeactive.org/submit/cheetah/

The short code did not lock the page and I then tried to lock the full page.

No luck.

I am doing something wrong but have no clue how to even describe it.
I therefore made short video - unfortunately the sound was muted but I am sure you'll get the idea.

http://www.screencast.com/t/ZmFiOGM3Yj

The video is 8m and 5 mins long.

Thanks