Here are steps to add a screen saver:
1. Open the Panel you want to add a screen saver to
2. Click the "Edit Pages" toolbar button above the Panel or right-click within a blank area of the Panel and select "Pages.."
3. Click "New" to add a page. Name the page anything you want. I named my page "screensaver"
4. Click the "Slide Show" button under Page Type to make the new page become a Slide Show. Answer Yes to the warning message.
5. Click the checkbox for "Screen Saver after" to mark this Slide Show as your screen saver page
You can add custom images to the screen saver or just leave it blank to display a black screen.