I was my at school browsing in the Apple section. They had a Macbook Pro 13 demo unit out and I started playing it, checking to see its durability. Everything has nice and solid except the screen. Near the center of the lid (where the Apple logo is), the aluminum is weak(?) and you can easily press down on it. And when you do so, you can see the LCD distorting. Is this typical? Or was the demo unit a bad one?