Hidden shademode is acting wierd

[karlkarpuk]

Hey!

I have a problem with the hidden shademode. The two pictures in the one i attached, are from the same file, the same model, the right one being a copy from the left one. Shademode is set "hidden", but as you can see, the effect is different in the pictures. I cannot figure out, why is that so.
Those are two different vieports with exactly the same properties.

Now when i observe the problem in modelspace (attachements 2 and 3), that happens: If i only have the left model zoomed in, the shademode works fine, but right as i zoom out so the copied model is in view as well, the shademode goes bizarre.

What seems to be the problem? Is it about the computer specifications?
I'll attach the file and my specs to the first comment.

[karlkarpuk]

My computer specifications and the file i'm working on are in the attachements.

Had to upload the file seperately because it is still too large (i deleted some solids and gave the file a random name): http://www.speedyshare.com/yATC5/123123123wesdf.dwg
(Click on the file name at the top of the page to download)

[Anonymous]

i opened your file and i'm seeing the same issue. both in 2011 and 2013. although 2013 handles it a bit better. very strange issue indeed.