Index: /FCKeditor/trunk/editor/_source/classes/fckeditingarea.js
===================================================================
--- /FCKeditor/trunk/editor/_source/classes/fckeditingarea.js	(revision 448)
+++ /FCKeditor/trunk/editor/_source/classes/fckeditingarea.js	(revision 449)
@@ -220,5 +220,5 @@
 			// In Firefox if the iframe is initially hidden it can't be set to designMode and it raises an exception
 			// So we set up a DOM Mutation event Listener on the HTML, as it will raise several events when the document is  visible again
-			FCKTools.AddEventListener( this.Document, 'DOMAttrModified', FCKEditingArea_Document_AttributeNodeModified ) ;
+			FCKTools.AddEventListener( oDoc, 'DOMAttrModified', FCKEditingArea_Document_AttributeNodeModified ) ;
 		}
 
@@ -230,21 +230,16 @@
 function FCKEditingArea_Document_AttributeNodeModified( evt )
 {
-	var oDoc = evt.currentTarget ;
-	var oWindow = oDoc.defaultView ;
-	var editingArea = oWindow._FCKEditingArea ;
+	var editingArea = evt.currentTarget.defaultView._FCKEditingArea ;
 	
 	// We want to run our function after the events no longer fire, so we can know that it's a stable situation
 	if ( editingArea._timer )
-	{
-		oWindow.clearTimeout( editingArea._timer ) ;
-		delete editingArea._timer ;
-	}
-
-	editingArea._timer = FCKTools.SetTimeout( editingArea._MakeEditableByMutation, 1000, editingArea ) ;	
+		window.clearTimeout( editingArea._timer ) ;
+
+	editingArea._timer = FCKTools.SetTimeout( FCKEditingArea_MakeEditableByMutation, 1000, editingArea ) ;	
 }
 
 // This function ideally should be called after the document is visible, it does clean up of the
 // mutation tracking and tries again to make the area editable.
-FCKEditingArea.prototype._MakeEditableByMutation = function()
+function FCKEditingArea_MakeEditableByMutation()
 {
 	// Clean up