Index: /FCKeditor/trunk/editor/_source/classes/fckiecleanup.js
===================================================================
--- /FCKeditor/trunk/editor/_source/classes/fckiecleanup.js	(revision 545)
+++ /FCKeditor/trunk/editor/_source/classes/fckiecleanup.js	(revision 546)
@@ -44,5 +44,5 @@
 function FCKIECleanup_Cleanup()
 {
-	if ( !this._FCKCleanupObj )
+	if ( !this._FCKCleanupObj || !window.FCKUnloadFlag )
 		return ;
 
Index: /FCKeditor/trunk/editor/_source/fckeditorapi.js
===================================================================
--- /FCKeditor/trunk/editor/_source/fckeditorapi.js	(revision 545)
+++ /FCKeditor/trunk/editor/_source/fckeditorapi.js	(revision 546)
@@ -157,5 +157,12 @@
 function FCKeditorAPI_Cleanup()
 {
+	if ( ! window.FCKUnloadFlag )
+		return ;
 	delete FCKeditorAPI.__Instances[ FCK.Name ] ;
 }
+function FCKeditorAPI_ConfirmCleanup()
+{
+	window.FCKUnloadFlag = true ;
+}
 FCKTools.AddEventListener( window, 'unload', FCKeditorAPI_Cleanup ) ;	
+FCKTools.AddEventListener( window, 'beforeunload', FCKeditorAPI_ConfirmCleanup) ;