iPhoto only showing one image from a digital camera or card reader

Problem

When looking at pictures in iPhoto from a Digital Camera or Card Reader it will only show one picture found instead of all of them.

Solution
The device needs to be reformatted:

1. Close iPhoto.
2. Open a new Finder window and go into the drive for your Camera/Card Reader.
3. Make a backup of all the pictures on there.
4. Go to the Applications folder.
5. Open the Utilities folder and open Disk Utility.
6. Click on the device on the left hand side.
7. Click the Erase tab on the right hand side.
8. Click the Erase button and wait for it to finish.
9. Once done, eject the device and take some new pictures.