Thanks, but both things didn't help.
I don't know whats wrong...Images look perfectly fine, and this is a fresh install of OS X. Anybody with a new c2d macbook have the same issue?
Edit: I'm not sure if grainy is the best way to describe it...and I'm not sure how to. The best I can do is give an example, like the circles that act as your password while typing it don't seem perfectly round, and when I zoom in on it, the pixels on the top of the circles look flatter then those on the bottom.