[IronPython] about auto type cast

[jeferslineage at gmail.com]

In my project,i use DataObject.Net(one ORM Library) to access
database.
My operater steps:
1.Deploy a .net remoting server
2.At frontend,i use ipy connect to server,just create a Domain object.
3.Create a DataObject Session Object
4.run command:obj=session[19],type(obj) return
DataObjects.Net.DataObject,
   session[19] return a Category Class(a subclass of DataObject),in
C#,i can use
   Category obj=(Category)session[19],but there kinda be no way in IP.
5.run command:Category.Name.GetValue(obj) ,type(obj) return
DePetShop.Model.Category

Why the type changed after 5 step?