Those programs are very dependent on how Explorer initialises the task bar, in what order messages are posted and how controls are named or laid out. It's not exactly a surprise that those things stop working, given that the program digs around in another program's internals. Besides, Windows 8.1 brings its own start button, so those programs have to be adjusted anyway to account for that.

Fun read: http://blogs.msdn.com/b/oldnewthing/archive/2003/12/23/45481...