The plugin TinyMCEComments doesn't seem compatible and I can't work out why.
http://wordpress.org/extend/plugins/tinymcecomments/
If I'm not logged in, like any user, then the little MCE bold/italic and other buttons do not appear. When logged in as admin, it does work.
I can simulate the effect for admin use by adding its two js files to the Minify setting.
http://pwnwear.com/wp-includes/js/tinymce/langs/wp-langs-en.js?ver=20081129
http://pwnwear.com/wp-includes/js/tinymce/tiny_mce.js?ver=20081129
I have no idea how to solve this, any help would be appreciated. My users really like having an MCE editor for their comments.