Are you using EJB 3 or EJB 2? EclipseLink does not support EJB 2 EntityBean, only EJB 3 Entities.
You cannot inject an Entity bean, it does not make sense, they must be queried from the database through an EntityManager. You can inject an EntityManager using @PersistenceContext.
See,
http://en.wikibooks.org/wiki/Java_Persistence/Runtime#Java_Enterprise_Edition