Dynamic pages unreachable

Hi, I created a public dynamic page…

…but I only seem to be able to access it as a logged on member, and not just any member, but the site admin. If I log out and try to access the page, I get this:

If I log on as another user who is not admin, I get this…

What am I doing wrong? I need the page to be accessible to everyone, even someone who is not a site member.