Currently, you have to either...
... to get back to the forum you were reading. Would be nice if there was a direct link back to the forum, either with a "Go" button on the Quick Nav dropdown, a "Back to Forum" button, or a duplication of the heirarchy at the bottom of a thread.
- scroll through the "Quick Navigation" full forum list dropdown OR
- hit either of the "Top" buttons and then click the forum name in the heirarchy