Suppose the layout of my buttons is currently

   (close) (minimize) (maximize) (title) (menu)

Now I bring up the Window Manager Settings. I now see that two buttons are hidden:

   (stick) (shade)

If I move any of the hidden buttons in any way (even if I just move the shade
button a bit to the right so that the ordering does not change), the layout in
all real windows is changed to

   (menu) (close) (title)

even though the layout on the preferences window remains identical to before.

(To reset the layout to conform to what the preferences say, similarly, simply
move the buttons in the "Active" frame in some way, even if the move does not
change the ordering.)