Here’s what worked for me. When I updated to 2.3.3 only the last 4 images in the visual editor’s menu bar appeared, and they didn’t work. I tried the suggestion given earlier to change the permission of the tinymce folder/directory (wp-includes/js/tinymce), changing it from 0775 to 0777. But when I went back to the Write Post page and refreshed it, all of the images disappeared, leaving only a white rectangle. I then changed the permission back to 0775, and when I refreshed the page again all of the images appeared and the editor now works fine. [Mac OS 10.2.8; Firefox 2.0.0.12]
