Screen Saver issues

I have selected Aperture (which I use to handle all my pictures - all 55K of them), in the source for my screen saver, but after doing this, I have not had it works since.

It simply "times out" and never shows any pictures, so I went to change it, but when I try to o so, it keeps saying "Source: Loading", in the selection in the "Desktop & Screen Saver" preferences. I can hear from my NAS that it is scanning for these pictures, but it never returns with the prompt to change the source.

Is there a place where I can reset the screen saver settings, and select something else in source?

This was not an issue before Mavericks, and as I am having problems with iTunes, when I sync my iPhones, in that it takes forever to sync photos (also Aperture and pictures on a NAS), I think something is up with the AFP interface I use for connecting with my NAS...

 

This is where OSX sits for hours...

http://www.flickr.com/photos/bokr71/11143902565/