Why does iPhoto keep corrupting my images?

Question

For the past year, iPhoto 11 has been tremendously buggy on my early 2011 15" MacBook Pro.  It started under Lion and has continued apace under Mountain Lion.  It first started going haywire and crashing every time I tried opening it after any premature removals or disk use of my camera card in July 2011.  After starting in safe mode and having to rebuild my library several times, it seemed to settle down, and would generally work as long as I restarted the computer after a crash.  However, many of my photos ceased to show up properly--either they wouldn't be there at all, or the pictures and/or their thumbnails would be rotated the wrong way, sometimes with the display dimensions reversed so they appeared improperly squashed or stretched.  This issue mostly affected photos from c. 2001-2005, which I'd brought over from my iMac to save space on the older desktop computer.  (The iMac is backed up with my Time Capsule, but I haven't yet tried to see how that works within iPhoto, nor from my MBP.)
In the past few months, both before and after the installation of Mountain Lion and some updates to iPhoto itself, iPhoto has been acting strangely again.  Whether or not there's any "misuse" of a camera card that precipitates iPhoto's misbehavior, it's often been saying that thumbnails are corrupt and need to be rebuilt, but instead of fixing them it makes even more of them look worse than they did before.  Especially annoying, it seems to have permanently squashed, stretched, and/or rotated most of the images I'd chosen as Event preview images--i.e., it's done the most damage to a lot of the best pictures in each event, and it's been hitting a lot of the more recent photos than the first set of bugs did.  In addition, it quits itself spontaneously at least once per day, and gives an error message when it does so.
I used to love iPhoto, but its behavior lately, and the way it's been corrupting or failing to properly display thousands of my pictures, have been frustrating beyond words.  Has anyone else had problems similar to mine with iPhoto lately?  I really wish I'd never "upgraded" to the current version, because the new functions shouldn't come at the expense of losing or having to manually rebuild and tweak thousands of photos.  Can anyone recommend a solution to stop this from happening further, and to get things back to normal?
Regards,
Brian Green

Answer 1

Where is your Library stored?
What rebuild did you do? iPhoto's own?
As a Test:
Hold down the option (or alt) key and launch iPhoto. From the resulting menu select 'Create Library'
Import a few pics into this new, blank library. Is the Problem repeated there?