Why doesn't my ControlTemplate get applied in the ItemContainerStyle?

Are the items you are adding to the control UIElements?

Took me ages until I found this obscure reference:

"The container for ItemsControl is normally a ContentPresenter, but if the child is a UIElement then it won't use a container. In this case, all of the children are Controls, so the ItemContainerStyle will apply to them directly. If you added an item other than a UIElement, that setter would set the Control.Template property on the ContentPresenter, which would succeed but have no effect."

http://stackoverflow.com/questions/3542381/specify-controltemplate-for-itemscontrol-itemcontainerstyle/3542399#3542399