Index: /CKEditor/trunk/_source/core/dom/domobject.js
===================================================================
--- /CKEditor/trunk/_source/core/dom/domobject.js	(revision 3196)
+++ /CKEditor/trunk/_source/core/dom/domobject.js	(revision 3197)
@@ -104,5 +104,5 @@
 						this.$.removeEventListener( eventName, listener, false );
 					else if ( this.$.detachEvent )
-						this.$.detachEvent( eventName, listener );
+						this.$.detachEvent( 'on' + eventName, listener );
 
 					delete nativeListeners[ eventName ];