Some of the images are scanned transparencies from medium format slides, output is to a TIF file. Epson Perfection 4870 used to scan. Other images are from a Nikon D200 or a D700. Latter can be NEF or TIF.
I tried changing the name of the slide that seemed to be the culprit. It started with "_DSC". Took out the underscore and shortened the file name to less than 8 letters and this seems to have worked. Does that give you any clues?