Excuse the intrusion, - just some info to add to the mix,
Am seeing an error - (firebug) - referring to edit_pages_page_contentStyles2.xml [ edit_pages_page_contentStyles2.xml ]
That page says 'XML Parsing Error: syntax error''
FCKConfig.StylesXmlPath = ''; // relative to fckeditor/editor/fckeditor.html'
(Should be a relative path to the edit_pages_page_contentStyles2.xml file) Not sure if this helps with a diagnosis.