It turns out that GetPreviousVisible returns bogus items *all* the time.
Creation sequence like this:
root node - <C wxTreeItemId instance at _3186e90_wxTreeItemId_p> first node - <C wxTreeItemId instance at _3187920_wxTreeItemId_p> second node - <C wxTreeItemId instance at _319a320_wxTreeItemId_p>
result of call to GetPreviousVisible on second node: <C wxTreeItemId instance at _3172d60_wxTreeItemId_p>
I don't know where that item came from, but it's no item that *I* added to the tree.
