One user on Apple’s forums has discovered problems when trying to export a presentation using the new H.264 codec in QuickTime 7. If you use the custom QuickTime export functions in Keynote and choose H.264 as the codec, Keynote will crash on export. While we’re not sure if this happens under Panther using QuickTime 7 (we assume it does) we’ve been able to reproduce it in Tiger.
The fix is to UNCHECK the box labeled “Key frame every _ frames.” Doing this allows Keynote to export the movie properly. Hopefully Apple will have a fix for this soon.