Sometimes when an app starts and creates a new non-maximised window, the new window is placed so that its title bar is underneath the Unity menu bar in the Unity stacking order. This is inconvenient for these reasons:
1. it is of doubtful utility to be able to ever move a window such that its title bar is off screen, because then it cannot be moved back without using the keyboard (alt+drag or alt+space to invoke a system menu, both of which are expert-level shortcuts)
2. even if it ought to be possible to explicitly position a window with its title bar offscreen if you, the user, know what you are doing, Unity choosing to do that makes it more complicated to rectify the problem if you are not an expert
3. for added user frustration, if the created application's menu bar is *empty*, clicking where the window's title bar looks like it is (that is: on the Unity menu bar) will actually select and start dragging the window *below* the new one, which likely belongs to a completely different application, because "our" application is not maximised and therefore can't treat a "drag" of the menu bar as being like a drag of the app's title bar.
See attached files for debugging details about Unity and a brief video demonstration.
It has been suggested that this is not a Unity problem; it is a problem specifically with either qmlscene or with Ubuntu SDK apps in qmlscene. I do not know how to verify this. Of course, even if an app demands to be moved to 0,0, I am not sure that Unity should allow it to put its title bar *below* the Unity menu bar.