Do you still have a copy of your original backup? If it's not too out of date, you can rename it and copy it to your Pictures folder. Then use iPhoto Buddy to add it and your current one to it's list of useable libraries. Don't open it yet, just select it with iPB and close iPB. Then launch iPhoto with the Command+Option+Shift keys depressed and follow the instructions to rebuild the library. It will ask you to name the new library folder so you can give it a distinctive name to identify it from the originals. That may get you thru the recovering each time. Worth a try.
Be sure to repair disk permissions after copying the iPhoto Library folder into the Pictures folder. Just a precaution.
If all efforts fail to get a stable, useable library you can use iPhoto Extractor to copy your full sized photos out of the library of your choice to three new folders on the desktop. You can then move all of the library folders out of the Pictures folder and create a new, fresh iPhoto library. Then reinstall the photo files from those three temp folders.
Hope this has been of some help. Good luck.