WPF - Very basic ListBox.ItemTemplate Question

Question

Ok, this is an embarassingly simple-looking problem, but is driving me crazy. I\'m learning about DataTemplating and am trying to apply a very VERY simple ItemTemplate to a List

Answer 1

For some reason DataTemplate can still be ignored if the ListBox is populated using ItemsSource e.g:

Note that this is bound to an ObservableCollection containing objects (TextAdapter : INotifyPropertyChanged) with one property: string Text {...}