Missing "Choose Folder" in OS X Screensaver Prefs


I'm having an issue with the built-in slideshow screensaver in OS X 10.3.9. I'd recently begun using it, selecting a particular custom folder with the "Choose Folder" option in the screensaver list in System Preferences. Today, however, I found that this option was completely missing from the list.

I haven't made any drastic changes or updates, so I have no idea why this occurred. I logged in as a different user, and the option was visible there, so I suspect some user-preference issue, but I checked again a few minutes ago and it is now gone from there as well. I hope you can help me out in getting it back.

--James Allen