Premiere Pro :: Importing Images Into CS5?

In an HDV project in CS5 Premirer Pro, I am importing images from a source file into the project window and then onto the timeline. These are separate jpg images, each one with a different filename albeit the first three letters of the filename are the same. When the images are imported, although the filenames are as they appear in the source folder, the actual images are all identical - usually to the first image in the group. It makes no difference whether I import the images separately or as a group - the same problem persists. I have tried clearing the media cache and re-starting the computer. No use.