I periodically go through my bookmarks and clean them up. I either delete them outright, or shove them in a folder called “Archives.” Or, at least, there used to be a folder called Archives. I moused over the folder in Firefox and found that all (but one) of my archived bookmarks were gone.
I’m not sure how or why most of my archived bookmarks got deleted — we did have a pretty nasty power outage today and my workstation died — but if my bookmarks file was corrupted, I’d expect it to be a total loss, instead of a partial one.
Luckily, the latest version of Firefox makes nightly backups of your bookmarks. I dug one out from the 5th, and my archives were complete. The file definitely changed yesterday (technically yesterday, the 6th). I’ve managed to get all of my bookmarks back thanks to the older version, but I am not happy to have lost my bookmarks in the first place. If FF didn’t have the backup function, I would have been SOL.