Going from EJB2 to JPA Made Us Discover Bad Data

It is funny, how going from EJB2.x CMP data access code to JPA ORM data access code in one of my projects, made us discover bad data.
Over a serious of years, this project has moved through EJB1.x, EJB2.0 and EJB.2.1. Our use of the old EJB standard have made the impact, that the domain modelling [...]