Convex NonTrigger Mesh Collider + Rigidbody = weird transform position

Sorry for my bad english

Hello, I’m new in Unity and I don’t know if it’s normal or a bug.

I have a Space Shooter Sample Project from Unity Technologies and Unity 5 does not Non-convex MeshCollider. OK I turned Convex and everything is fine (transform is 0, 0, 0).

But if I have Convex MeshCollider with not Trigger then transform is (-1.421085e-14, 2.235174e-08, 1.788139e-07) and every frame it change x and z value.

How it is possible and can I fix it?

Convex meshCollider + rigidbody it’s not possible in unity anymore.
You should find another way of doing it.
Anyway it normally gives a warning.