Could you explain more about "does not recognize"? Does this external drive show up in the Folder Panel at all?
Are you sure that when you look for the photos and don't see them, that you have selected "All Photographs" and turned filters off? If, in "All Photographs" and filters turned off, you search for a specific photo by its file name (which you can determine from your operating system), can you then find it?
And please please please, just because I'm a horrible person, you must tell me your operating system.
