is my videocard broken? or could it a driver problem...

Hello,

i have startet working with the Tutorials from Mbsoftworks and i have a problem with the culling from the demo programms…
tutorial where i have made a screenshot from you can see what it should look like in the link, and this is what it looks on my PC:
[ATTACH=CONFIG]602[/ATTACH]

I have a nvidia gtx 560ti with the latest drivers. On a PC with a gtx560 and older driver it works…
is there a way to figure out what the problem with my PC is?