Index: _source/plugins/wysiwygarea/plugin.js
===================================================================
--- _source/plugins/wysiwygarea/plugin.js	(revision 6985)
+++ _source/plugins/wysiwygarea/plugin.js	(working copy)
@@ -1078,6 +1078,13 @@
 
 								iframe.clearCustomData();
 
+								// IE9 might cease to work if there's an object selection inside the iframe (#7639).
+								if ( CKEDITOR.env.ie9Compat )
+								{
+									var sel = editor.getSelection();
+									sel && sel.getNative().clear();
+								}
+
 								/*
 								* IE BUG: When destroying editor DOM with the selection remains inside
 								* editing area would break IE7/8's selection system, we have to put the editing