I'm trying to follow the advice in the monitor adjustment tutorial regarding midtones. But no matter how I fiddle with the brightness and contrast settings, the square on the left always blends best with the gray background, and both the middle and the right square appear lighter.
My monitor is a relatively modern LCD (but definitely on the cheap side):
http://www.viewsonic.com/products/va926.htm
It has a sRGB setting and I normally use that, but the above is true in that mode as well as in the default 6500K mode.