I wish someone would give some advice on this as I am having the exact same problem. Importing a timeline from FCP 7 via Boris FX AAF transfer filled with jpeg’s. The “thumbnails” are long stills being used as a guide for the animatic. All audio comes in fine, as well as a couple .mov files – just not the jpegs. The error it’s kicking out is ‘Exception: IMPORT_TOO_SHORT’