ListView Grouping question (?)

Hello,
I have a ListView and when I bind an ObservableCollection to it, it groups exactly as I want and that is great.

Now there is another ListView I have, let's call it myListView and I add Items to it as follows:

        myListView.Items.Add(new myObject(... my parameters here));
        myListView.Items.Add(new myObject(... my parameters here));
        etc ...

If I try to group by

       myListView.Items.GroupDescriptions.Add(new PropertyGroupDescription("Name"));   <-- Let's assume I have a"Name" property

the ListView's IsGrouped is false and also NO GROUP HEADERS show up no matter what! I can not use the GroupDescriptions on the ListView itself, otherwise I would and I think that would solve the problem.

Any ideas?

Thanks for your time,

Noorbakhsh