Log files
Whenever you perform any operation that alters an iPhoto library, such as copying albums, merging libraries, finding duplicates, or importing photos, iPhoto Library Manager will create a log file containing basic information about what's going on as the copying takes place. You can access these log files by selecting "Show Logs" from the Window menu. In the folder that is revealed, you will see a separate log file for each copy operation that you've done using iPhoto Library Manager. The name of each log file consists of the date and time that the operation began, followed by a brief description of the operation (e.g. "2009-04-09 093421-Merge (Hawaii, Florida) into 'Vacation'.log") The files will open by default in the Console application when you double click them, but they are just plain text files, and can be opened in any other program that can read text files, such as TextEdit or Microsoft Word. Log files that are older than thirty days will automatically be cleaned up by iPhoto Library Manager, so that your logs folder doesn't accumulate new log files forever.
If any errors occur during a photo copying operation, they will be reported in the message that is displayed by iPhoto Library Manager after the operation has completed. If you want to get more detail on what errors occurred, you can open up the log file for that operation and search for the word "error". If any photos were missing from the original library and thus could not be imported into the destination library, a search for the word "missing" will let you find exactly which photos were missing. You can also search for the word "duplicate" to find out which, if any, photos were skipped as a result of having the "Don't import duplicates" preference setting enabled.