Keynote will not re-record from a point in the middle of a slide show.

If you want to narrate a keynote presentation and need to re-record a slide you must re-record from that slide to the end. Since I have upgraded to Sequoia I find that Keynote refuses to record audio from any slide to the end. You can go through the motions, but when "Play recorded slide show" is chosen the presentation will simply stop at the point where the new audio was supposed to begin.

Anyone else notice this?

Before Sequoia I found "Record Slideshow" behavior to be haphazard at best, unless a presentation was recorded from beginning to end without stopping. Now, at least, it behaves consistently.