Did you save it under a different name?

It's a long shot, but it might help you get what you want.

This doesn't make sense. Like J. Adrian said, check for a different file name. Also check to see the location of the new audio file. When you go to play back the file, check the date on the file, make sure it's the most recent.

Thank you Adrian and Jeffrey for your suggestions.  I did locate some stray copies of the earlier version of my piece on my computer, and deleted them.  Now an .aiff file of the revised version is indeed created -- but in fragmented form!  That is, random notes are continuously left out! I've tried this a few times, including converting the .asv and .bak files that Finale automatically creates, always with the same fragmented result. Any ideas on how to repair this glitch?  

Gotta figure out the problem first. No doubt there's something amis but anything that keeps repeating is not a "random glitch". There's a cause.

What (if anything) do the omitted notes have in common?

Instrument? Range? Duration? Articulation?