There was a time when I used to reference masters.
There was a day Aperture Guru's convinced me to let Aperture manage my images.
There was a time I had thousand of images.

One hour ago, I was working with Aperture, made an undo, and Aperture told me that there was a inconsistent data in my library. "You have to relaunch Aperture and rebuild the library".
Then, all my library has gone.
Yes, I had plenty of space to work on my hard drive, since Aperture decided to free up the space filed with my images.

What to do now?
I am restoring a Vault (From two days ago). So I lost just two days of work, but tomorrow, I have to deliver some work, with images that, of course, I don't have anymore, but a few I exported to photoshop.

Then:
Maybe try Lightroom.
Maybe will back to iView Media Pro (AKA Microsoft expression) and Photoshop combo, as before.

I suspect I'll can't rely anymore in "Let me manage your media" applications anymore.
If a 2.1 version is not mature enough for a basic task like avoiding deleting content by mistake, why should I trust all of my adjustments and metadata.

This is the first time, in a long, long time using Apple, that I consider myself betrayed by my Mac.
Even more. I can't remember an Issue like this on my PC times. Even with viruses involved.

I know it is my responsibility to do backups. I do it. But I can't do 34GB backups diary. (don't have enough space, and disks for keeping several copies).

Should I trust Apertures Vaults (Faults) Time Machine Backups if Apple keep track of files like within Aperture?

Sorry people at Apple. I really consider this a black hole in my Mac history.

Sorry to hear that, leohans.

By searching for "lost images" in the Aperture forum on the Apple website, I've found a number of discussions on this topic. Also, I'd suggest you re-post this topic in our photography community forum, where you'll find quite a few seasoned Aperture users.

Maybe, with the information available from those two sources, you'll be able to also restore the photos from your Aperture library that you hadn't backed up yet and maybe find out what, exactly, was the cause for this problem. Best of luck!