如何让Castle MonoRail的DataBinder / SmartDispatcherController绑定到包含接口属性的类型？

We're using interfaces to represent entity classes in our domain model. We have concrete implementations of these by virtue of using LinqToSql. We have added a factory method to each LinqToSql class which our service layer uses to instantiate a new entity (note; as opposed to the controller's DataBind attribute doing it).We're using interfaces to represent entity clas