Just got a dell 19" display for my macbook. I want to make it so I can use 1440x900, but every time i do that a big chunk of the screen is cut out, but not when I make it 1360x768, it says it support 1440x900, so what's going on? Am I missing something? can anyone help? I also want to make it a dual screen if at all possible... here is what it looks like... and yes the dock is on the right side, flush with the edge