Self-playing. Video stops after 2.5 seconds

I've got a slideshow with mostly stills and one 44 second video. Converted to mp4 file using H.264 codec.

In manual (Normal) mode, the video plays through. But when I set to self-playing with 2.5 seconds per slide, the video only goes for 2.5 seconds then onto the next slide.

What's the trick? Keynote '09.

I looked at other discussions. I tried "go to KN prefs and checked "Allow Expose, Dashboard and others to use screen* which had no effect. Turned of Perian.

Thanks for any clues.