Odds are that the bug is half-Windows half-Reaper.
On everything up to XP, programs get to paint their contents directly on the screen, all by themselves. If you move a window, the one under won't update until it hears the alarm clock saying "get up, start painting again", and you get those awesome streaks and glitches.
Vista makes everything paint to a buffer off-screen and then does the actual painting itself, so it can remember what the window looked like the last time it got painted. This is also how Vista can do the fancy 3D-flipping-around effect and give you taskbar thumbails.
This bug is raping my eyes
Linear Mode
