Custom BindingList<T> question

Hello;

I have a question related to implement a Custom BindingList<T>, I'm using .NET framework Beta 2.
My custom class is declared as:
public class CustomBindingList<T>: BindingList<T>

Using my custom class I see that it expose a AddNew() method which returns to me new initialized item.
Reading the help for this method gave an understanding on how this method works, but in really in my code it works different, so I'm not really sure if I just misunderstand it. From help I understand the following behaviour:
1.- Calling AddNew returns me a new item, but it's not added to Items internal list until I explicitly call EndNew method, or it's never added if I call CancelNew. If I'm right what happens with the Count property of the binding list after AddNew, but before EndNew or CancelNew

From my code I can see the following behaviour:
1.- Calling Addnew it returns a new Item, the AddeNew it's not overrided in my implementation, but AddNewCore is:
        protected override object AddNewCore()
        {
            return base.AddNewCore();
        }
1.1.- After calling base.AddNewCore I saw that binding list call InsertItem, which is overrided:
        protected override void InsertItem(int index, T item)
        {
            base.InsertItem(index, item);
        }
       
But my question is why does it call InsertItem, if I understand right it must be called after EndNew.

The code that use my custom collection is:

            BindableCollectionBase<TestEntity> col = new BindableCollectionBase<TestEntity>();

            TestEntity newItem = col.AddNew(); // Inside this method it calls the InsertItem method
            newItem.Name = "AllowNewTrueCollectionIBindingTest";
            Console.WriteLine(String.Format("Adding item: {0}", col.Count)); // This line displays that my collection has one item
            col.EndNew(col.IndexOf(newItem)); // I'm expecting to have one item, but after calling this method.
           
Any help would be really appreciated.
Thanks
Mario Chavez