Copy materials in file with same material names

Please help.

When I copy objects with (flamingo) materials in a v6 rhino model with the same material names, I want the pasted material to be duplicated, instead of the new object get the same material properties as the material that was already in the model.
In my rhino v5, when I copy a material name like ‘New material 001’ to an new model that contains the same material I get ‘New material 001 (01)’ as a new material.
How can I achieve this also in rhino v6?

You can duplicate materials in the materials panel

I Know, but my problem is that when I import objects in my drawing the material properties changed to the excisting material properties. So when I import objects from my library I have to change the properties, because it is changed while imported in drawing.