The audio for the FLV and the slide should be playing at the
same time (unless you put a delay on the video). To verify, in
Presenter, go to the slide that you are having issues with, select
Edit Video. At the bottom you should see the effects options. Tell
the video to start after the audio. Republish and see if your auido
is there, but was some how drowned out by the FLV. If that was the
case you may just need to boost the volume of your audio to be
louder than the video, but that may cause it to sound like noise.
As a final option, try putting the FLV on a slide following
the problem slide. This will disassociate any relationship between
the audio on your slide and the FLV,
Jorma@RealEyes