When the taskbar is positioned at the top of the display and a hot key is used to position and size windows, the windows are displaced downward by the number of pixels equal to the taskbar height (30 pixel for a single height taskbar or 60 pixels for a double height taskbar).

That is, the top of a window is located 30 or 60 pixels below the bottom of the taskbar, and the bottom is displaced by the same distance. Thus, the bottom of the window is positioned below the bottom of the display. The total height of the windows are correct.

If the taskbar is at the bottom of the display, it works fine.

I love the multi-monitor taskbar addition.

This also happens if the taskbar is located on the left side of the monitor, and only on the monitor with the taskbar.

Okay, the problem is not with the taskbar but with windows placement (using Ctrl-Win-Q to center a window) on the screen with the windows taskbar it is incorrectly calculating the offset needed to place the window in the center of the window. I have attached a screen shot.

Here is an example of the result when doing Ctrl-Win-W (Make Window Full Screen). The Window is displaced downward by the height of the Taskbar. The bottom of the Window is off-screen.