Index: /FCKeditor/trunk/editor/_source/internals/fckdialog.js
===================================================================
--- /FCKeditor/trunk/editor/_source/internals/fckdialog.js	(revision 1609)
+++ /FCKeditor/trunk/editor/_source/internals/fckdialog.js	(revision 1610)
@@ -190,5 +190,6 @@
 
 				this.HideMainCover() ;
-				topDialog = null ;
+				// Bug #1918: Assigning topDialog = null directly causes IE6 to crash.
+				setTimeout( function(){ topDialog = null ; }, 0 ) ;
 				this.SelectionData = null ;
 			}