First of all, Moose, someone will probably merge the posts. (Also you can edit your own posts, fyi.)
Second, I've had a bit of a problem along these same lines. Basically the text box on the post page doesn't follow the rules. (Neither does the quickreply box.) If you use the expander at the bottom, instead of actually expanding the window usefully, it just drags it down, which covers up everything below it except the "Preview" and "Send" buttons.
I have some ideas about this, but I'll be honest, I'm too damned lazy to install XAMPP and a phpBB install on my laptop just to check.