Maybe a bug - circle positions not exact saved

[Drachenbauer]

Hello

I created a "plinko" - part (many little circles, oriented in a triangular grid-pattern, wich slow down the fall of the marbles and make them move left or right) in my marble-race.

But if i save and reopen it, or do some modifications in another area of the race-track, i often find some of the little circles not exct in the grid-positions any more.

I use the grid-function of Algodoo to make my stuff with exect sizes and perfect fit together.
So i don´t like plinko-circles, wich are not at the exact grid-positions (maybe a marble can get stuck, if the circles move to close together because of this bug).

In the next room on the race-track i´m creating a rotating-flowers-plinko (the flowers should fling the marbles randomly through the room with their petals, until they find their way down to the exit).
Different to the circles of the common plinko, theese flowers stay exactly in their positions.

Is there any way to fix this and keep the circles on their exact positions?