Error when opening iPhoto '08: Photos Have Been Found in the iPhoto Library That Were Not Imported

While copying our photo library from our PC to the Mac, I started getting the above error whenever running iPhoto '08. The number goes up seemingly randomly. If I click No then iPhoto opens as normal. If I click Yes then iPhoto attempts to import these photos, even asking what I want to do with duplicates before quitting at some random point in the import.

After searching discussion forums, I found a solution:

There were files that had gotten "stuck" in the import process, causing iPhoto to crash when recovering the files every time it launches.

To get get rid of them, right click on the iPhoto Package File in the Pictures Folder and choose 'Show Package Contents'. A Finder window will open and you may see in there a folder called 'Importing' with these pics in it. Drag it to the desktop and then relaunch iPhoto. Then you can decide what to do with those files.