I am using Dozer to map between a Document class to DocumentManagementBean class, both of my own making. Both have a property, with getters and setters, of Joda DateTime type, c
I think the root cause is that DateTime is immutable, so the deep copy cannot be done (see https://github.com/DozerMapper/dozer/issues/216).
That's why you have to use a converter or copy it by reference.