As an addendum to this, players should note that "side issues" could also be driver issues. For example, someone mentioned that if you had a picture as your wallpaper, you may see similar problems. This is correct, but only because the video driver is not doing things correctly.
Under ideal conditions, the driver (or, DirectX, if that's in place) should "take over" from the background wallpaper. One can think of this as a sort of "layering" effect. The game map "sits on top of" the wallpaper, which is a JPG at a different resolution. In theory, it just just do a background resize of the wallpaper, fitting it to the screen. But, if the line-draw or some other video function isn't working perfectly, "strange" things can happen inside programs which are also using the same video functions (like, scrambling bits, pixellation, etc.)
So, the moral of the story is: If in doubt, check for new video drivers.
At LAST! The greatest campaign board game of all time is finally available for the PC. Can my old heart stand the strain?