I have iPhoto 8.1.2 grayed out in OS X 10.9.1 screensaver, both internal HD and external on iMac. I have tried reinstalling OS.
How do I use iPhoto as a screensaver?
Update iPhoto first. That might solve the problem. I am running the latest iPhoto and OS X and it allows me to select Photo Library-which then brings all iPhoto stuff (Events, Photos, Faces, Places, etc.)