Hibernate impl. of JPA 2.0 spec generates extra inner joins on the base of named queries for human tasks. It causes empty results on retrieving task assigned to group.

When I start TasksServer (i.e. Mina) in J2EE environment (EJB 3.1 and JPA 2.0) hiberbate generates 2 extra inner joins in query for group tasks:

inner join OrganizationalEntity user7_ on task0_.actualOwner_id=user7_.id
inner join OrganizationalEntity user8_ on task0_.createdBy_id=user8_.id

So group tasks have empty values in actualOwner_id and createdBy_id columns (because it's group task) and result of this query is always empty.
Problem exist for following queries:
TasksAssignedAsPotentialOwner
TasksAssignedAsPotentialOwnerWithGroups
TasksAssignedAsPotentialOwnerByGroup
SubTasksAssignedAsPotentialOwner

This problem is described here: https://hibernate.onjira.com/browse/HHH-5518

Need to modify named queries in human task