I noticed a JavaScript error on the "Add Comment" link for this answer. I've never seen the behavior on any other answer before, but clicking the link produces the following error in Firebug:
w.find("textarea").charCounter is not a function
var vote=function(){var l={informModerat...t.documentElement.scrollTop}}})(jQuery);
Because of the error the comment frame never displays and a comment cannot be posted.
Update
Sorry I didn't mention it initially... I receive the error in Firefox 3.5.7. I do not receive the error in Chrome or Internet Explorer 8.
Update 2
Whatever the problem was, it has ceased now when I click that link. I have seen it approximately once more since I initially reported the issue, but it has been several weeks. If I see it again I'll update this post.
...
in there?