Hi Michael,

Thank you for quick reply and looking into this!

I did further research on this and some of discussions on The Foundry forum enlightened me. It turns out that this is caused by MODO and it seems to be one of the known issues that The Foundry is working on.
The problem is that the PIVOT of the MESH is automatically transformed immediately after MODO imported LWO from MoI. I'm not smart enough to explain why pivot position affects shading,
but all I have to do is to delete additional pivot transformation channel from item/channel list then the artifacts disappear (or cut MoI mesh and paste in new mesh layer works as well).

I believe MoI doesn't do any harm.
So I'm sorry to take your time, Michael.
I'm now very happy that I don't need to be afraid of modeling transparent objects in MoI since some of my modeling tasks is a lot easier in nurbs than subD.

Thanks,

Hisashi