I seem to have run into the same problem with 5.0.8, albeit in a more simple form:

With enableLazyInitialization, a list annotated with @OneToMany(mappedBy="foo") is null after fetching. The other side of the association is annotated with @ManyToOne(fetch=FetchType.LAZY, optional=false).

When i disable the enhancement, the list is being populated again.