Hi Mike, can you help me better understand the issue here? If you are observing that the adapted TreeView doesn't retain a memory of its state-of-expansion after posting back... then this is a known limitation of the current TreeView adapter. It's already something that I've got on the to-do list for a future rev of this sample kit. Basically, it involves sending a bit more info (concerning what is expanded) back to the server during these postbacks so the server can restore the expansion state when the page is sent back down.
There is some intersection between this feature and another to-do item: populating the TreeView nodes upon demand, rather than always having all the nodes defined all the time. Hopefully, we can nail both of these enhancements to the adapted TreeView code in a not-too-distant rev of the adapter kit.
Meanwhile, maybe someone in the community of forum readers would like to suggest some code we could stick in the current CSSFriendly.MenuAdapter with some cut-n-paste magic.