OnDeleteAction cascade fails with constraint violation error

Question

Hibernate 3.3.x

@Entity
public class User {

    @OneToMany(mappedBy = "user", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    @OnDelete(action = OnDeleteAction.CASCADE)
    @Cascade(value = DELETE_ORPHAN)
    @OrderBy
    private List<Phone> phones= new ArrayList<Phone>(0);
...
}

Cascade delete is not enabled if you have some phones for a certain user. If the phone list is empty, this seems to be working fine. It fails with a foreign key violation error on the User reference from Phone. What am I missing here?