diff -r 5882f0eebb34 -r e3b94bd055dc includes/clientside/tinymce/plugins/preview/editor_plugin_src.js
--- a/includes/clientside/tinymce/plugins/preview/editor_plugin_src.js	Mon Dec 21 15:41:05 2009 -0500
+++ b/includes/clientside/tinymce/plugins/preview/editor_plugin_src.js	Tue Dec 22 13:09:59 2009 -0500
@@ -1,5 +1,5 @@
 /**
- * $Id: editor_plugin_src.js 895 2008-07-10 14:34:23Z spocke $
+ * $Id: editor_plugin_src.js 1056 2009-03-13 12:47:03Z spocke $
  *
  * @author Moxiecode
  * @copyright Copyright © 2004-2008, Moxiecode Systems AB, All rights reserved.
@@ -24,7 +24,7 @@
 					height : parseInt(ed.getParam("plugin_preview_height", "600")),
 					resizable : "yes",
 					scrollbars : "yes",
-					popup_css : css.join(','),
+					popup_css : css ? css.join(',') : ed.baseURI.toAbsolute("themes/" + ed.settings.theme + "/skins/" + ed.settings.skin + "/content.css"),
 					inline : ed.getParam("plugin_preview_inline", 1)
 				}, {
 					base : ed.documentBaseURI.getURI()