I typically leave the unit up and running 24/7. In my Win power settings, I changed the desktop hard drive setting never to shut down when the computer is turned on, thinking maybe that was the problem. The screen saver errored out a couple of times that day, so I figured that wasn't it.

But since that day, the screen saver slide show just keeps running like a champ. Go figure.

Maybe the hard disk setting didn't go into effect until the system was rebooted and an overnight Win update rebooted the system?