It sound like you have a corrupt iPhoto Library. I don't feel you can conclude the 3rd party software is corrupt yet, as it clearly sounds like a corrupt iPhoto Library.
When a library is corrupt, it is not uncommon for it to show the exact same thumbnail for multiple images.
You post indicated you have 10.8.2 OS. What version iPhoto are you using?
You can attempt to fix your iPhoto Library by using the "built in first aid" for iPhoto. It is slightly different for the different version fo iPhoto.
Note - Apple does recommend you create a back up of your iPhoto Library, as a precautionary measure, before troubleshooting the iPhoto Library.
- quit iPhoto and all other open applications
- hold down your "option + command" keys on the keyboard, and keep them held down while launching iPhoto. This should launch iPhoto with a "first aid" screen over top of it. Do each of these first aid steps, one at a time, until you have completed all the steps.