I'm using Cocos2d (0.99.5) with chipmunk physics engine. Currently I'm trying to place a body into space which is combined from few circle shapes.

Let's say I have a corresponding sprite image with displays atom (nucleus + 3 electrons around it. Something like this without orbit lines). In it's simplest form - only one circle shape at the center should be enough which would detect collisions from other objects with nucleus. Now I'd like to add other circle shapes for each electron. How can I do that?

Now when I add those shapes to the body and add the body into chipmunk space - the shapes (together with the body/sprite) start flickering and spinning with no recognizable pattern (or reason for that matter).