I try to use the Q&A plugin for the main site of my

Hi,
I try to use the Q&A plugin for the main site of my wordpress multisite network but some thing must be wrong in my settings and I don't know where.

When I am not logged, I works fine and I can see all the answers and questions in my Q&A pages.
But if I log in as administrator of one of the blogs and then I try to see the Q&A pages, I am always redirected to the "Unauthorized Access Page" that has been set up in the Q&A setting page.

Do you have an idea why an administrator of one of my blog is not authorized to see Q&Q pages ?