I combined three iPhoto libraries, and had LOTS of duplicates.
How did you combine those three libraries? Did you import those libraries into a library? If so that imports the modified, thumbnail and original files of the imported libraries as if they were original files.
The only way to merge libraries is to use iPhoto Library Manager to merge them.
The description/comment field is in the Info tray that expands out of the right side. Just type Command+i to bring it out.
You solved it! Found the photos and deleted them! Just to be on the safe side I threw them off on a DVD just in case duplicate annihilator got a little over earnest. But from the reviews I see that it does a pretty good job.
Oddly enough, Library Manager created a bunch of duplicate albums which turned out to be empty. I have to go in now and delete all of those. But that is a small job.
BTW, while I'm in Chicago, my brother lives in Temecula. Beautiful place!
All the best and thanks!