Iphoto '09 version 8.1.2 (424) quitting unexpectedly ALOT

Question

I know something in my iphoto is corrupt, because it keeps quitting and I have to restart it many times a day.
Also, some of my recent photos are blacked out during a slideshow, so doesn't that mean that they're corrupt?
I'm backing up to a Passport once a week, but I'm afraid to backup and restore from it, as I've never done that before.
I feel like I need to rebuild the iphoto, but that's scary, too. What can go wrong with a rebuild? How hard is it to do?
I have 1,000 Events, 16,015 photos, and 771 movies. It's 46.3 GB. I don't care about the events, but the photos and movies
are very important.
Can someone walk me through the process?
Thank you in advance.

Answer 1

If Larry's rebuild doesn't work:
Download iPhoto Library Manager and use its rebuild function. (In early versions of Library Manager it's the File -> Rebuild command. In later versions it's under the Library menu.)
This will create an entirely new library. It will then copy (or try to) your photos and all the associated metadata and versions to this new Library, and arrange it as close as it can to what you had in the damaged Library. It does this based on information it finds in the iPhoto sharing mechanism - but that means that things not shared won't be there, so no slideshows, books or calendars, for instance - but it should get all your events, albums and keywords, faces and places back.
Because this process creates an entirely new library and leaves your old one untouched, it is non-destructive, and if you're not happy with the results you can simply return to your old one.