I just mapped a component B that only has a collection in it (bag) to a class Foo

I deleted all the elements of the collection and then made Foo.B = null;
The problem is that when I retrieve the Foo at a later time the component is != null. I've read that the component should be null if all properties are null. The case seems to break since the Bag collection is always != null because nhibernate initializes it.

Is there a way around this issue?