I'm unable to use HTML editor with 2.x

Everytime I place the HTML Editor control, many of the other controls goes invisible and page stops working properly.

Can anybody help ?

No matter where, I use the HTMLEditor tag, it just make it worse.

Also, i tried to use CKEditor but unable to get it working with AJAX update.
I mean if I'm trying to update it using Ext.net button, then its not working. :(

Please help.