http://www.youtube.com/watch?v=YeDaF1hsS_cI just downloaded a few days ago, bought yesterday, didn't download anything else..
Whats your specs?
Go to the start menu and click 'Run...' and type in dxdiag, once the DirectX Diagnosis Tool finishes checking your hardware, you should see two tabs towards the top of the window, one labeled System and another one labeled Display, in these two tabs is where you'll see your RAM, processor, and graphics card
WAIT. I got it. It's the lights. This happened on my old laptop, but now I have teh Mac.It's a REALLY simple fix. Turn both dynamic lighting options in the advanced options off.
It works. :3
http://www.youtube.com/watch?v=Fl_tLDEFGGU&feature=related