I'm running Mac OS X 10.6.8 and noticed for a long time that with my dock positioned on the bottom of the screen in Hiding mode and a window open, there is a sliver of my desktop showing through on the bottom. Yet if I move my dock to the left or right, then I can stretch the window to completely fill the screen. Is this a 10.6.8 bug or something? Is this issue there in Lion? I don't feel comfortable with my dock on the left or right side of my screen, I want it on the bottom but without the desktop showing through.