Hibernate version: 1.2.0.Alpha1

My class has some collections that should support many-to-many association. So, I use <bag> to map my property.
If I use IList to declare collection - all OK.
But I need to make basic collection class that implements IList.
And when I have tried to do it I have caught exception with message: "Unable to cast object of type 'NHibernate.Collection.PersistentBag' to type 'VL.DataStorage.UsersCollection'."

I feel that I should use collectionPersister but I don't undersatnd how I can do it correctly. Have you any suggestion?

Here are a few posts from our development mailing list discussing how it's supposed to be done: http://sourceforge.net/search/?ml_name=nhibernate-development&type_of_search=mlists&group_id=73818&words=user+collections