jboss-EJB-3.0_Preview_5\docs\tutorial\singleinheritance\src\org\jboss\tutorial\singleinheritance\bean\PetDAOBean.java has:

public void createCat(String name, double weight, int lives)

{ Dog dog = new Dog(); dog.setName(name); dog.setWeight(weight); dog.setNumBones(lives); manager.persist(dog); }

where is creating a new Dog instance and NOT Cat.

Same for the tableperinheritance and joininheritance.