Isn't it possible that the thumbnail portion of the Jpeg looks OK in playback yet the serious part of the image is corrupted? Viewing Jpegs on my cameras and zooming always looks different from the view on the computer. If you can, also try to do the equivalent of a 'scandisk' of the card, to check all data areas. BTW, whereas flash is not corrupted by magnetics as are mag disks and tape, they still have vulnerabilities, even tho rarely encountered. Static electricity is one, tho rare on CF due to the packaging, but still possible.