No, that's not the case. I've actually never really touched the example patch. Anyway, my actual worry is why these objects behave the way they do in my patch, which is really strange. In order to see what's wrong I opened earlier versions of the patch I'm working on (which were using [link] and [mass] fine) and they also show the same strange behavior. It looks like a bug hit it all of a sudden..
I've attached an earlier version which is smaller, if anyone's willing to check. Physical modelling is inside [pd object1], [pd object2] etc. inside [pd coordinates1]..
It used to be that the first time you hit the bangs, the rectangles wouldn't behave as expected (in the gem window), but after that everything was working pretty stably. Hope someone can help.