What I do is go to the "advanced" editor, then click the "Switch Editor Mode" button in the top right corner of the toolbar. That's the button with two As, one in normal type and one in blue italic underlined. When you do that, you get the full WYSIWYG editor.
That said, the feature might not work with all browsers. I vaguely recall trying to use it in another forum a few years ago, and found that it worked in IE but not in the early version of Firefox I was using at the time.
Does that help at all?