My catalogs are backed up to two separate sets of backup disks nightly, so I've never lost any images... And I NORMALLY write all the changes to the files before I shut down at the end of the day... I learned this when I corrupted a catalog a long time ago and had to rebuild the whole thing. Fortunately, I'd saved all the metadata, so it was annoying but not disastrous...
I actually have only a few catalogs... They are stored with the previews in a separate partition that ONLY holds LR catalogs. All were updated/upgraded when I installed LR4 a goodly while ago.
- One is my regular images, which is in a folder tree all by itself.
- In a separate folder tree called "other" is the rest of the catalogs.
- One of these is "family" so I don't clog up my images with a lot of gunk from family stuff.
- Another is "theatre", which is images of theatre productions for clients.
- "Cat Shows" is a catalog of it's own that only contains images from cat shows I photograph. This is the one that had the problem the other day.
- And finally is "temp", which is an empty one that gets used on those very rare occasions when I want to put images in a catalog and I'll be getting rid of them.......
There are, as far as I know, no other catalogs anywhere on this box... I never have to go hunting 'cause everybody shows in the list of catalogs when I start LR.
The images weren't lost, they were, and are, all in their normal place, and all came UP in the catalog when I started Lightroom... What WAS missing was one session's changes, all made on the same day, but not written out to the files...
I didn't see any error popup, or anything bizarre, and there were 1100 files changed in the cat show catalog that day, but for whatever reason, they didn't show in LR when I restarted a session the next day... BUT, in Lightroom's defense, it's ALWAYS POSSIBLE THAT THERE WAS AN ERROR, OR I DID SOMETHING AMAZINGLY STUPID... 'Cause I've done pretty much every imaginable thing wrong at one time or another... So, I don't think there's some major, bizarre problem with Lightroom.