When I turn on Direct3D 8 mode and an object moves over an object with a blend coefficient set, it creates this motion blur type effect that I'm guessing shouldn't be present. In Direct3D 9 it doesn't happen, but I want to use 8 because it doesn't get forced to blend all the pixels like 9 does on a computer like mine when the application display is resized to fill the window.

Below I've included an image capturing what I'm talking about. You'll probably need to click to enlarge it so you can actually see the blurs.