Being connected on libervia, you can not leave to another page
Firefox 21.0
You're connected on libervia, try to leave the page by entering any URL in the address bar and enter, using the navigation history, opening a bookmark --> you're still on libervia!
If you're on libervia but not connected (login screen), the behavior is as expected: you can leave the page.
I'm not sure if this should be considered as a bug or a functionality... it's after all not a bad idea to force the user properly close the session before leaving the page. But I'm not sure if he will understand it.