I like to use events and albums from iPhoto as my screensavers. Lately, only some events and albums show up when I go into preferences>screensavers. If I go out and come back in, most will then show, but once I choose an event or album it doesn't reliably show up when the screensaver should start. I get message that folder is empty of pictures and to choose a different one. Suggestions?
I would verify that your iPhoto library is fully intact. To do this:
You'll be presented with a Rebuild Photo Library window. I would check the following options:
If the issue persists, I'd take a look at this article on Mac OS X Hints and follow the steps listed there.