Index: /FCKeditor/trunk/editor/_source/internals/fckselection_ie.js
===================================================================
--- /FCKeditor/trunk/editor/_source/internals/fckselection_ie.js	(revision 826)
+++ /FCKeditor/trunk/editor/_source/internals/fckselection_ie.js	(revision 827)
@@ -86,7 +86,14 @@
 
 		default :
-			var range = FCK.EditorDocument.selection.createRange() ;
+			var doc = FCK.EditorDocument ;
+			
+			var range = doc.selection.createRange() ;
 			range.collapse( startBoundary !== false ) ;
-			return range.parentElement() ;
+			
+			var el = range.parentElement() ;
+			
+			// It may happen that range is comming from outside "doc", so we
+			// must check it (#1204).
+			return FCKTools.GetElementDocument( el ) == doc ? el : null ;
 	}
 } ;