Hi Ditto, yeah when the selection mechanism targets an object, it will go by what is the closest one to the mouse.

Stacked objects can have just very slightly different pixels drawn for them, especially if they are not totally identical like if one is some shorter fragment than the other. So slightly different pixels drawn on the screen for an object can result in that kind of behavior that you were seeing.

Usually it is a good idea to try and hide things that are getting stacked up though - try to get in a kind of habit of hiding things that may get in your way earlier rather than than later.

- Michael