JPEG Saver 5.22.1
If you are one of those people who like to wait for the .1 release, then this is the version for you. Actually, it's for anyone who downloaded version 5.22 as well because it fixes a crashy bug.
All the changes in this version are related to the metadata scan. The most important is that the screensaver was quietly crashing after completing the metadata scan at times. Not all the time though - only when it had already scheduled a burst of metadata to be scanned before the current burst had completed the scan.
The next problem was that the improved metadata scan in version 5.22 also meant it was quite slow to start up, which held up loading images, which in turn caused navigation to fail, staggered multi-monitor updates to not be staggered, and some other annoyances. I've split the startup into smaller parts so this won't be a problem again.
I also found that checking a single video file's metadata could take a really long time, so I've disabled it for video files for now. I might have to move the metadata scan into its own thread to get around this.
And finally, the metadata scan was skipping over images that have records in the database but are no longer on disk. Now it removes them from the database so it doesn't try to scan them again.
JPEG Saver 5.22.1 is available from the downloads page.