Rebuilding a corrupted iPhoto library
If you have an iPhoto library that is corrupt and causing iPhoto to crash or otherwise be unusable, iPhoto Library Manager provides the ability to rebuild your library based on the information found in its library data files. Note that iPhoto also has a built-in rebuild function that can be sometimes be used to repair a corrupted library database. You can find instructions on how to use that on Apple's website at http://support.apple.com/kb/HT2638 (iPhoto 6 or later) or http://support.apple.com/kb/HT2042 (iPhoto 5 or earlier).
iPhoto Library Manager's rebuild works differently, in that instead of trying to repair the library in place, it creates a brand new library and tries to reimport the entire contents of the original library into the new one, including reconstructing albums, photo metadata, etc. Note that rebuilding a library has all the same limitations as other photo transfer operations as far as what can and can't be copied between libraries. Also, depending on how badly damaged the library is, iPhoto Library Manager may or may not be able to piece together some or all of the library metadata.
To start a rebuild, select the library you would like to rebuild, then choose the "Rebuild Library" item from the "Library" menu. You will be prompted to choose a location for the rebuilt library, and whether or not you want iPLM to scavenge orphaned photos it finds in the library package. Once you've made your choices, iPLM will examine the library and rebuild the library structure and photos as best it can, then display you a preview of what it was able to find. If your library is badly damaged and the preview is missing a lot of content from the original library, this can save you from going through with a rebuild that won’t end up being of much help.
Once you've had a chance to examine the preview, if you want to go forward and create the rebuilt library, click the "Rebuild" button in the upper right. iPhoto Library Manager will create a new library and start importing the contents of the original library into the new one.
In some cases, either the iPhoto library database is too damaged for iPhoto Library Manager to be able to salvage any information from it, or the library data is incomplete and there are photos that still exist inside the library package, but iPhoto has lost track of them. In these cases, you may want to check the "Scavenge orphaned photos" checkbox when choosing a location for the rebuilt library. After iPhoto Library Manager has read the library data as best it can, it will perform an additional pass through the package and locate any photos that are no longer referenced in the library database. Any additional photos that are found will be included in the rebuild, and a new "Scavenged Photos" album will be created in the rebuilt library containing any scavenged photos.