Page specific visibility settings Show block on specific pages:

I have tried to use this feature and simply can not get it to work properly. I am not sure that it matters but I have installed drupal into www.mysite.com/main. When I select "Show on only the listed pages." and type into the text box, it works fine. However, if I type a created content page like it does not work.

Can someone please help, I am quite a basic user here so any help would be great!!