I'm getting an ugly exception when performing a simple join. It's an StringIndexOutOfBoundsException in org.hibernate.hql.CollectionSubqueryFactory.createCollectionSubquery(), but the problem seems to be in org.hibernate.engine.JoinSequence.toJoinFragment(Map, boolean, String, String). There's more info in the bug report (which was already created for me) in http://opensource.atlassian.com/projects/hibernate/browse/HHH-1830 . Hope it helps, thanks!