OK, --Back to the drawing board.
I downloaded QTPro and the newest version (3.8.2) of Fotomagico.
Opened the slideshow file, which has 265 images and 15-20 music clips (played sequentially) from various sources.
Went to File >Share. With the QT upgrade, one of the options now included QT movie. Selected NTSC and widescreen. Ran program--about 15-20 minutes to make QT movie. Result is .mov file, 6.3 gb. Opened file, and lo! the movie plays.
Then tried to copy the movie to a flash drive. No luck. Got a message: "Sorry, the operation could not be completed because an unexpected error occurred (error code 0).
Thanks for the fantamorph link. Looked there, but it sounded too complicated for me. Afraid I would create new problems. Anyway, I have sidestepped the error -1409-- only to create a new one!
Update: Learned that error code 0 resulted from tryin to copy the 6.3 gb movie to a FAT32 formatted flash drive. Reformatted to OSX extended journaled and the file copied properly. But must go back and figure out what format (cropped or letterbox) provides the correct image proportions.
Many thanks for your help!