IPhoto 8 Photos Corrupted or Disappeared

Question

Using iPhoto 7.0.2 (341) I've now had two separate iPhoto libraries where photos were either corrupted or lost.
In the first instance I noticed a problem trying to do a Retrospect Back-up and the procedure simply hung the program. Then when I tried to copy the whole library via the finder, the copy was interrupted with the message: "The Finder cannot complete the operation because some data in "IMG_0416.JPG" could not be read or written (Error code -36)"
When I went into the library and tried to export the picture via the file menu, I was unable to do so. When I dragged the photo to the desktop, it seemed to go across but when I opened it in preview it was a partial photo and garbage.
When I tried to duplicate the picture in iPhoto, I was unable to do so. I ascertained that there were close to 200 photos from several loads that I couldn't duplicate. This was from uploads back in March of this year.
In this instance, I did have a prior version of the library backed-up. I deleted the photos I couldn't duplicate and then imported versions from the prior back-up. It seemed to fix the problem, at this point.
In the second instance, a different library, the photos simply disappeared from two separate imports. For import #1 (about 30 photos), the thumbnails were still there but when I double-clicked on the thumbnail, I got a greyed-out image with a exclamation point. In import #2 (about 70 photos), there were no thumbnails visible, just a faint outline where the photo should have been. Double-clicking on the thumb-outline got the same greyed-out image. These were recent imports, 2 and 1 weeks ago.
In both instances, I had gone in and corrected many of the photos and deleted others -- the program seemed to be working just fine until the photos disappeared.
The photos were completely gone. Import #1 was available as a back-up. Import #2 is lost and gone.
Can any one tell me what's up here? I'm extremely nervous about using iPhoto at this point -- it seems that at any time my work could simply disappear. Can any one suggest what's wrong?

Answer 1

mbabc:
How much free space do you have on your boot drive? It's strongly recommended that you maintain a minimum of 10G free space, more if possible.
Try the following;
Move the existing library folder to the desktop.
Open the library package like this.
Launch iPhoto and, when asked, select the option to create a new library.
Drag the Originals folder from the iPhoto Library on the desktop into the open iPhoto window.
Now check to see if you have all your pictures and that they are useable. Once satisfied you can delete the old library folder/packages.
Do you Twango?
TIP: For insurance against the iPhoto database corruption that many users have experienced I recommend making a backup copy of the Library6.iPhoto database file and keep it current. If problems crop up where iPhoto suddenly can't see any photos or thinks there are no photos in the library, replacing the working Library6.iPhoto file with the backup will often get the library back. By keeping it current I mean backup after each import and/or any serious editing or work on books, slideshows, calendars, cards, etc. That insures that if a problem pops up and you do need to replace the database file, you'll retain all those efforts. It doesn't take long to make the backup and it's good insurance.
I've written an Automator workflow application (requires Tiger), iPhoto dB File Backup, that will copy the selected Library6.iPhoto file from your iPhoto Library folder to the Pictures folder, replacing any previous version of it. It's compatible with iPhoto 08 libraries. You can download it at Toad's Cellar. Be sure to read the Read Me pdf file.