When I try to write a comment in quick succession after another, I get the expected "you gotta wait 15 seconds" notification in orange.
That's fine; I can wait. Ish.
But the "Add Comment" button is also disabled, and it cannot be re-enabled; I have to copy my comment to the clipboard, refresh the entire page, then try again.
(This appears to be new since at most a couple of days ago.)
(Firefox 8.0.1, Windows 7)