In case someone has the same problem, I fixed my screensaver issue by uninstalling the simple screensaver hack, then uinstalling the old custom screensaver hack, then uninstalling the jailbreak. Then reinstalled the jailbreak. After copying my images to my hard drive, I deleted the "screensaver" folder in my KT USB root drive. I reinstalled the simple screensaver hack, and it created a new "screensaver" folder with the standard KT pens and pencils images. (And I also think I made a mistake in including the .png extension in the names of the images for the simple hack, which shows you how ignorant I really am.) So all is good now.
Thanks to the gurus who created the jailbreaks and the hacks.