I am trying to publish my DAOs into web services and I am having some problems:

When a collection is implemented by an IList<> interface, it works fine until it is published by a Web Service (this is obvious). The Xml Serializer can not handle interface definitions.
It is not possible to solve by implementing a generic List configuring the NHibernate collection as a field and exposing the generic List implementation, because the "bag" collection could not be serialized too.

Please, does anybody know the best strategy to handle this issue?

Thanks in advance.

interface cannot be serialized,therefore
this code work:

and this no:


"bag" collection is serialized: