Don’t know what has happened, but the “Leave a comment” form after each post doesn’t work right now. The pop-up comment form still works, so if you would like to leave a comment, please use that mechanism. To do so, click on the “Comments (moderated)” link at the bottom right of any post where you wish to put up a comment, and the pop-up will, uh, pop up.
Sorry for the inconvenience. I’m looking into the problem, which is proving elusive. Fortunately, issues that may have been broader in scope seem to be under control now.