<p>Happened to me on 5D. These are not present on the original preview and not visible on the camera screen. They are generated when PS re-creates previews from the raw files.<br>
The only way I have found to "fix" it is to direct my Bridge to the card in the card-reader instead of the copy on the disk. Looks like it is necessary to re-generate the images on the card itself. On the other hand, it was happening on all cards, so I'm not sure about my explanation, but the "solution" worked.</p>