Ticket #6408: 6408.patch

_source/plugins/autogrow/plugin.js

@@ -14 +14 @@
                         newHeight;
 
                 // We can not use documentElement to calculate the height for IE (#6061).
+                // It is not good for Quirks, yet using offsetHeight would also not work as expected (#6408).
                 if ( CKEDITOR.env.ie )
-                        newHeight = doc.getBody().$.scrollHeight + 24;
+                        newHeight = doc.getBody().$.scrollHeight + ( CKEDITOR.env.quirks ? 0 : 24 );
                 else
                         newHeight = doc.getDocumentElement().$.offsetHeight;