http://bugs.winehq.org/show_bug.cgi?id=23591
--- Comment #8 from Nikolay Sivov bunglehead@gmail.com 2011-05-14 09:07:00 CDT --- Seems to me it's a problem with wrong expand/collapse logic. When item has no children we shouldn't send TVN_ITEMEXPANDING but we do.
I'll take a closer look.