For me, the "X" in the lower right corner works, also "ESC" works.
I'm using FireFox 17.01.
I tried the same thing in IE 7, but the "X" and ESC worked there, OK.
(There was some menu weirdness in IE 7, but I've seen that elsewhere. A menu that should have run left-right along the top of the screen runs up-down near the left margin. But you can't count what IE 7 does wrong as a bug - more like "expected non-conformance".)
>> I'm not expecting any reports, though.
If it was anyone else, I would say "pride goeth before a fall", but based on his track record, I'm not betting against Dave.