tested with twentyeleven, and it brakes the Editor-Functionality:
1.) Textcolor is now Backgroundcolour: white.
2.) Switch Tab from HTML to WYSIWYG does not work.
3.) Wordcount is constantly set to zero.
4.) Adding new Tags is not longer possible.
5.) Series- Editor should be shown under the Editor, but its missing in some Articles.
Switching of the Plugin, and Point 1 to 4 is working fine :-/