PowerPoint encountered an error and needs to quit when opening exported Keynote presentation

Version: 2008
Operating System: Mac OS X 10.5 (Leopard)
Processor: intel

I have attempted to export my Keynote presentations to PowerPoint, but when I open these files in PowerPoint I get the error message:

"PowerPoint encountered an error and needs
to quit.To save a copy of the current prsentation, on the File menu, click Save As and give the document a new name.Save any other open presentations, and then quit and reopen PowerPoint."

I am running the Office 2008 12.1.0 and Keynote 08 (v4.0.3).

I have read on other forums that deleting all the presenter notes results in the presentation opening successfully. I use presenter notes heavily and this is not a satisfactory answer.

Exported presentation is opened and viewed fine in Windows PowerPoint Viewer (on Vista), Open Office (on Windows) and Google (when I email it to myself, I can click 'view presentation' and it displays correctly). Because the file seems to work in older versions of PowerPoint as well as competing products I am lead to believe it is a problem with PowerPoint 08 for Mac.

Has anyone else encountered this problem? I was surprised to find so few discussions about it, but the discussions I did find matched my situation exactly.