Index: /CKEditor/trunk/CHANGES.html
===================================================================
--- /CKEditor/trunk/CHANGES.html	(revision 5379)
+++ /CKEditor/trunk/CHANGES.html	(revision 5380)
@@ -144,4 +144,5 @@
 		<li><a href="http://dev.fckeditor.net/ticket/5504">#5504</a> : [IE6/7] 'Paste' dialog will always get opened even when user allows the clipboard access dialog when using 'Paste' button.</li>
 		<li><a href="http://dev.fckeditor.net/ticket/3601">#3601</a> : [Safari] Bad performance when drag editor chrome resizer.</li>
+		<li><a href="http://dev.fckeditor.net/ticket/4476">#4476</a> : [IE] Inaccessible empty list item contains sub list.</li>
 		<li>Updated the following language files:<ul>
 			<li><a href="http://dev.fckeditor.net/ticket/5326">#5326</a> : Catalan;</li>
Index: /CKEditor/trunk/_source/plugins/indent/plugin.js
===================================================================
--- /CKEditor/trunk/_source/plugins/indent/plugin.js	(revision 5379)
+++ /CKEditor/trunk/_source/plugins/indent/plugin.js	(revision 5380)
@@ -11,4 +11,7 @@
 {
 	var listNodeNames = { ol : 1, ul : 1 };
+
+	var isNotWhitespaces = CKEDITOR.dom.walker.whitespaces( true ),
+		isNotBookmark = CKEDITOR.dom.walker.bookmark( false, true );
 
 	function setState( editor, state )
@@ -188,4 +191,9 @@
 					   followingList.getName() in listNodeNames )
 				{
+					// IE requires a filler NBSP for nested list inside empty list item,
+					// otherwise the list item will be inaccessiable. (#4476)
+					if ( CKEDITOR.env.ie && !li.getFirst( function( node ){ return isNotWhitespaces( node ) && isNotBookmark( node ); } ) )
+						li.append( range.document.createText( '\u00a0' ) );
+
 					li.append( followingList );
 				}