should be using JavaSE-1.6 VM, and .classpath, codegen.targetPlatform, compliance and source should also all be 1.6
<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.0"?>
<!--
<copyright>
</copyright>
$Id: plugin.xml,v 1.1 2009/02/05 00:31:08 wpaul Exp $
-->
<plugin>
</plugin>