Screen saver doesn't turn on after explorer crashes

I have my power settings set so the screen saver comes on after 10 minutes, and the display turns off after 15 minutes. Everything starts off hunky dory. Though whenever I add a monitor or change resolutions there's a 50/50 chance I'll get a "windows explorer has stopped responding, windows explorer is restarting" error. Once that restarts my screensaver/power options won't start again until I reboot the computer.

Previewing the screen saver works, but it won't start up by itself.

Changing or resetting the power plans has no effect.

The screensaver and some of the power functions are handled by the video drivers. Update those if possible.

If those video drivers are already up to date, then let's start looking for a reason for explorer restarting. Use Process Explorer to see you we can find an app that is exiting and taking explorer down with it. You can change one setting to make it easier to see such an app:
File > Options > Difference Highlight Duration
...set that to 9 seconds.

If Process Explorer does not help, then take as many things out of the equation as you can via this process: Troubleshoot Application Conflicts by Performing a Clean Startup

If a clean boot does not stop explorer from restarting when you change screen resolutions then spend some time with these steps: Troubleshooting Steps for Windows 7