exporting from keynote 08 to powerpoint 08

I prefer to build presentations in Keynote, but most of the world uses PowerPoint so I often need to export from Keynote. With the most up-to-date versions of each, PowerPoint could no longer open Keynote exports, failing with an uninformative error message if loaded from finder or failing silently if loaded from PowerPoint's File menu.

There is a lot of discussion about this on the Mac forums with little concrete resolution. For me, removing the speaker notes from the Keynote version fixed the problem and my exports worked again.