I've been doing this for some time, however something about the latest build causes massive problems. Open this page along with others in a set, where this page is not the first or the last in the set. Close windows starting on the left until you come to this page. Wait for the 'flap' on the upper right to appear. Now try to close this tab. Note that tabs no longer respond.
The symptoms make me think this is a duplicate of bug 16623. *** This bug has been marked as a duplicate of 16623 ***