It's working great.  Thanks for your help.

I was actually a little surprised to see that we expose the HotTrackingNode as a settable property, but that is the case, and will solve this problem:

void ultraTree1_AfterSelect(object sender, SelectEventArgs e)
{
    UltraTree tree = sender as UltraTree;
    tree.HotTrackingNode = null;
}

Thanks for your help, I'm almost there.  I've implemented a BeforeSelect event handler and in it I set the 'old' selected node's Override.HotTracking property to 'true' and the 'new' selected node's Override.HotTracking property to 'false'.  This solves the problem of the HotTrackingNode appearance overriding the SelectedNode appearance.  The problem I have left is that when I click on a node to select it, it retains the HotTracking appearance until I scroll off of it, at which point it takes on the SelectedNode appearance.  How can I force the node to take on the SelectedNode appearance during the BeforeSelect event handler?