Index: /CKEditor/trunk/_source/core/htmlparser/element.js
===================================================================
--- /CKEditor/trunk/_source/core/htmlparser/element.js	(revision 2952)
+++ /CKEditor/trunk/_source/core/htmlparser/element.js	(revision 2953)
@@ -113,4 +113,7 @@
 			{
 				var attrib = attribsArray[ i ];
+				// IE's treated expand fields as dom attributes, skip it
+				if ( CKEDITOR.env.ie && attrib === '_cke_expando' )
+					continue;
 				writer.attribute( attrib[0], attrib[1] );
 			}