Extend TreeNode, place on Clipboard, do not pass Go
File this one in the Bugs category of your long-term memory:
You can extend a TreeNode and place it on the clipboard, and the clipboard will tell you it's there, but you can't retrieve it. This is a known (but not well enough) bug. It's times like this that I really wish publicly acknowledge bugs were in a place other than nested nine layers deep in a message in the newsgroups.