Some users report that they are unable to see the “Add Page Element” links in their Template | Page Elements tab. This occurs when the blog incorrectly tries to display from a URL with “www2” instead of “www.” To work around this problem, simply remove the “2” from the URL.
Update, 5/24: If you are still experiencing this issue but do not have a "2" in your URL, then there may be JavaScript causing the "Add Page Element" links to disappear. Please ensure that you put all JavaScript into JavaScript page elements, instead of directly into your template code.
