Can't use the Disqus Plugin

Hi! I’ve been trying to use the Disqus Plugin, but I only can see it working when I’m logged in. When somebody that isn’t logged in tries to post a comment, receives this message: Sorry, the built-in commenting system is disabled because Disqus is active.

In fact, the disqus comment box doesn’t shows up for logged out users, it seems that I’m the only one who can see it.

I’ve been testing with this url: http://www.nossoprimeirobebe.com/10-passos-para-emputecer-uma-mae-de-bebe/

Thanks!
Janaina