Merging and object losing OneToMany relations(in view)

[zer]

I am using Spring MVC 3, JPA and Hibernate.

I have an object A having a list of B. In domain class A I have:

@LazyCollection(LazyCollectionOption.TRUE)
@OneToMany
private List<B> list_Of_B;

When I display A on the view (jsp), everything is fine, I have the list of B.
But then I want to save A and return to the view of A.

Saving is done using an entity manager(in the DAO, called by a service, called by a controller):
@PersistenceContext
EntityManager em;
...
em.merge(A);

In controler, after we save A, we return to the same view of A.
But this time, we lose all the list of B(just on display, the relationship exists in db).

Do I need more annotation on the list of B ?
Thanks in advance.

[zer]

EntityManager.merge loses all the OneToMany

Any work around?