Index: /FCKeditor/trunk/editor/_source/internals/fcktools.js
===================================================================
--- /FCKeditor/trunk/editor/_source/internals/fcktools.js	(revision 1016)
+++ /FCKeditor/trunk/editor/_source/internals/fcktools.js	(revision 1017)
@@ -79,5 +79,6 @@
 FCKTools.FixDocumentParentWindow = function( targetWindow )
 {
-	targetWindow.document.parentWindow = targetWindow ;
+	if ( targetWindow.document )
+		targetWindow.document.parentWindow = targetWindow ;
 
 	for ( var i = 0 ; i < targetWindow.frames.length ; i++ )