Hi,
I have this porblem :
I have a class A with two different associations towards a class B
(ie, one with role1, and one with role2)
Then I try to save A, and I want to save or update (or not ) B.
So I defined two one-to-many relationship with the option cascade="save-update".
But when it happens that the same instance of B is associated with the two different roles to the instance of A I want to save I get a :
"Another object was associated with this id (the object with the given id was already loaded): " because it first does a create and then wants to update the second one.....
Moreover, I don't want to know if the B-end association is the same one on the two roles.....

How can I avoid this problem ?

No, you are mistaken. You have two instances, both with the same id.

It is because I am in a disconnected mode.

If I understand you well
You Load an object graph (A -> Bs where Bs contains B)
You close your session
You add a B snapshot (ie same id, version) from the outside world into A -> Bs2
You open a session
You save A and it fails because B with this id is already in the graph.

I don't know how to solve this in a layered architecture where the top layer don't know of hibernate.

The solution could involve lock()ing existing Bs before retrieving A, so that you preserve identity

The only workaround I found was to check progammaticaly before saving if the instances are identical. And then associate the two roles with the same instance.
If there is any better idea....