I want to move my photos to an external hard drive because my MacBook Pro's hard drive storage is almost maxed out. Only some images seem to export successfully at Jpegs. Others export as white, blank icons, no jpeg suffix to the filename, and when I try to open them in Preview I get a message about Color Sync not being able to handle. Photoshop wont open them either. However I can still open the unexported originals, ie the photos still in the iphoto library, with Preview or Photoshop, and within iPhoto they behave like photos which exported successfully. Ive tried exporting as original (what is this)? and as J-peg with similar unsatisfactory results. When I export these problematic images as Tiffs, it works out, but the images get way too big.