I'm try this script out

http://wiki.unity3d.com/index.php/Gravity

and I'm having some issues with it (it seemed to work when I tried it with an old version of unity)

the first issue is of collision, the objects (in my case spheres) will stick into each other rather than just touch.

and the second is that when the objects collide one of the objects with continue it's trajectory.

I'm thinking of rewriting the script from scratch unless someone can explain what's wrong with the script that i've got.