I just got my new Dell 2005FPW and I love it, but I just have a question regarding adjusting the contrast. I currently have it connected via DVI to my PowerBook, and can adjust the brightness, which I've brought down to zero, but the contrast adjuster is greyed out in the on-screen display, and the contrast buttons on the PB keyboard do nothing. Will I need to use the VGA interface if I want to lower the contrast? Thanks.