I got the last non-unibody MacBook Pro where it has a full DVI port rather than a mini DVI port. I've plugged a non-Apple DVI to VGA adaptor and plugged it to my Dell monitor via VGA. But top of the screen is kind of like shaking. So I am wondering if I should get an Apple DVI to VGA adaptor? Does it do anything special that the non Apple adaptor does not? (I think it came with one but I can't find it, so I probably have lost it...) Thanks.