It's still not working, and another technical problem has started. The forum doesn't accurately display when there are no new posts in a thread any more. I.e. in a threads list page, a dark blue icon means that there is a new post since the last time you looked, and a light blue icon means that there isn't. Dark blues now often show when there are no new posts.

And yet another technical problem. The Submit button, when posting a message, doesn't always work. It is often treated as the Review button. One time today, it took 5 clicks on the Submit button to actually get the post posted.

Far too much fiddling without fully understanding things, methinks.