The scenario is pretty much what was originally described. To illustrate, I took your "BringIntoView_WPF" example from the SDK, and added PreviewSelectionChanged="TreeSelectionPreview" to the RadTreeView:
sender, SelectionChangedEventArgs e)
var item = e.AddedItems
var parts = item.Name.Split(
(parts.Count() != 4)
Now, if you click 126.96.36.199 (successful select), then click 85.1 (not selectable), and mouse over 85.1.1, you get the attached picture. I don't want 85.1 to have a box around it; it wasn't selected, it has no special status.