Export and import?

My lamp shade was showing huge normals - even once I tried to adjust the size. So I froze it's transformations, now it shows black in the viewport. It renders fine though.

I've tried unnasigning and assigning materials, no difference.

Also, I tried to export then import it. Upon import, I get a warning advising me the it contains faces containing faces shared by multiple groups. I get that often, though I am carefull with modeling, and have cleaned it up.

Anyone able to help with these issues - especially the black display.

cheers

gubar