Rich text editor brokes validation framework

Recently I am writing my own blog engine with CastleProject MonoRail + ActiveRecord. One of the issue I come across is to get rich text editor work with it. While I can find 2 very featured rich text editor, the one I am using suffer from breaking fValidate and really easy field validator. Indeed I think most of these rich text editor will do so because they all overlay an editable frame on your textarea, which means the original validation effects set on the textarea would no longer display properly. I guess thats the reason why 37signals choose to use a wiki style formatting script.

If anybody have good resolution please comment, it would be more than welcome.