The solution would be to uncheck it? That's just a change, not a solution.
That means the statistics would be accessible to everyone that figures out the URL or knows Plesk. That's not something you want, or something that we can present to our customers.
Our customers can't log on to their stats with Plesk 11 (Windows), because the USER login does not work for that. But the user login does work for the panel.
Are you going to fix that?
/Caspar