shading problem

This happens after the Realistic shading of the 3D solid is rotated several times, using 3Dorbit command, in AutoCAD 2013. It never happened with previous (2011) version. Does anyone have an idea what causes it or how to fix it?

Graphics card/driver?

System specs?

Thanks JD. It is a desktop comp. with an on-board ATI Radeon HD 4250 card on Windows 7 Ultimate, 32 bits, 4GB RAM. I'll find out tomorrow about the graphic card driver.

I was thinking that it was related to the difference between 2011 and 2013 versions of AutoCAD. I tried playing with all kinds of settings but the problem is still there. When I tried zooming in and out repeatedly, it scrambled the surfaces of all kinds of shading too. It is pretty consistent. It renders the surfaces well but once you start moving the object, it comes back like you see on the picture.

.... Windows 7 Ultimate, 32 bits, 4GB RAM. .....

Did you install this OS (it is very rare these days to have a 32-bit OS)?

This is not my computer. I don't know the history of the OS installation.

The graphic card driver has been updated to AMD Catalyst 12.4, sometime in the spring.