Index: _source/core/dom/range.js
===================================================================
--- _source/core/dom/range.js	(revision 5853)
+++ _source/core/dom/range.js	(working copy)
@@ -1552,6 +1552,10 @@
 			// Do nothing if the boundaries are in different block limits.
 			if ( !startBlockLimit.equals( endBlockLimit ) )
 				return null;
+			
+			// Do nothing if the boundaries are list item 'li'	
+			if ( startBlock.getName().toLowwerCase() == 'li' && endBlock.getName().toLowwerCase() == 'li')
+				return null;
 
 			// Get or fix current blocks.
 			if ( blockTag != 'br' )