Simple Silverlight question: I have an ObservableCollection<MyObject> in my viewmodel. Every MyObject has a Label property. If I bind a ListBox to the collection and set DisplayMemberPath to Label, or set the ItemTemplate to a TextBlock that binds the Text property to Label, all works as expected.

If I change MyObject so it derives from a UserControl, the Label text no longer shows up in the ListBox; each item just shows up as a blank strip a few pixels tall. Why is this? There's obviously something I'm missing here about how different things get rendered.