I am having trouble changing my login screen background. I can select the default wallpaper, the Kde-default one, but whenever I select my own custom wallpaper, there is no image, just a solid color. Normally, I would just ignore it, but the thing that bugs me is that this is a fresh install of Kubuntu 12.04 64bit, and the OS before this one, the one which I overwrote, had no trouble using the exact same image as the background.
In the System Settings application, Login Screen settings, Background tab, enable background, Under "Background", selected Picture, under options, selected Position: Scaled. Colors: Single Color. Blending: No Blending.