How do I stop/remove screen saver photos in default collections?

I installed Mavericks with no problems, however, I want to get rid of the screen savers/default collections. The desktop/wallpaper seems to be working fine: it rotates through my own "desktop pictures" collection. However, I have been unable to eleminate the default collections photos from the screen savers. In System Preferences the source for screen savers is my "desktop pictures" folder, and my photos do come up, however, all the default collections photos are mixed in. If I uncheck Shuffle Slide Order, the default collections photos come on first.

Now, here's the mystery: I deleted (with a Secure Empty Trash) the default collections photos! The folder is empty. I've also put all the

com.apple.screensaver..... plist files in the trash. But they aren't deleted. Where are these photos coming from? Why do they still show up? What do I have to do to get rid of them? I've searched the hard drive (as best I can) using a couple of the file names, but nothing comes up. Would I get a better search by using Terminal?