The Tab configuration in sef administration doesn't work if the JCEditor is enabled, showing only "ARTIO joomSef Configuration global writeable".
if someone found this problem just change the editor, and maybe o core team of joomsef can see later..

I think that the file is administrator/components/com_sef/views/config/tmpl/default in code
<?php
jimport( 'joomla.html.editor' );
$editor =& JFactory::getEditor();
echo $editor->save( 'introtext' );
?>
submitform(pressbutton);

hugs

Well, we are using JCE as well and it works fine.
Can it be related to your browser? What browser are you using?

I am using firefox 3.0 in ubuntu.

Well, I have exactly the same :-), but everything works fine for me, with JCE or without.
So I guess the problem must be somewhere else, but no idea where.

Can you send a screenshot or page source or something?

I uninstall and I am using the core sef joomla, I will install joomsef again and will send for you ok?
I would like ask you some things, can you answer me by this topic?

I will try, go ahead. :-)