I have had the same problems with FCKeditor and AJAX as the rest here, but I happen to like using AJAX in the modules that I write!
But one fix I fould to work with Rich Text: When you have en FCKeditor on a page/module, then you just have to register the "Update" button (or any other controls that might want to send the contents of the editor to the server) to use a full postback to the server instead of a partical update. (It is also the recommended fix for FileUpload controls and other controls with AJAX problems.) Like this line in your Page_Load():
DotNetNuke.Framework.AJAX.RegisterPostBackControl( ___name_of_update_linkbutton____ );
Of course, I would much rather have an editor who could use AJAX :-)
MVH
Allan K. / webmaster, www.miniatureville.com