If one cannot downgrade QuickTime, then different method is needed.

To produce a QuickTime movie with the narrations from a recorded Keynote presentation perform the following steps.

1. First export a Keynote presentation to a movie.

2. Open the exported movie by QuickTime Pro and export it to a QuickTime movie (select export movie to a QuickTime movie).

These steps yield a movie that can be opened by iMovie. This movie, however, does not have narrations anymore.

3. To export also the narration, right-click the Keynote file, and select to view the package content. Then open the narration track with iTunes.

4. Add the narration from iTunes to the exported movie in iMovie.

This results to a QuickTime movie playable on iPods, iPhones and other computers. I wish that Apple would soon correct the apparent bug so that Keynote would export directly to a playable movie.