Please upgrade to 2.2 here.
The 2.0 and 2.1 branches are no longer being updated.
Whenever I enable this plugin, the edit box doubles everything I type. It's hard to explain, but basically the top box (where I'm typing) is html and then there's like a bottom box that is the WYSIWYG version. Is that how this plugin is intended to work? It's very disconcerting.