Creating a public Members directory with CiviCRM in Wordpress using Profiles
I assume you are seeing this as an anonymous visitor to the site and it fuctions properly if you are logged in.  If this is the case, I think you'll need to add anonymous users as able to see the information for these public profiles.  In CiviCRM go to Administer > User and Permissions > Permissions (Access Control). Select the 'Wordpress Access Control'.

You can provide anonymous users (all visitors to the website who have not logged in) permissions such as:


create and edit profiles ( or profile listings and forms) 


This is typically on by default, so someone might have turned it off.

See the Book for more details:

http://book.civicrm.org/user/current/initial-set-up/permissions-and-access-control/

Alternatively, if you cannot see the page properly as an authenticated user, or if this permission is given, something else may be amiss.

For a starting point, here are some unresolved forum posts with the same issues:

http://forum.civicrm.org/index.php/topic,34677.15.html

http://forum.civicrm.org/index.php?topic=30429.0

This could be a bigger bug that needs reported/fixed