activex PowerPoint Application Saving as ".ppt" default, not ".pptx" ?

I am trying to write a powerpoint using activex and in doing so specify the name of the file I would like to save as something like 'MySlides.pptx'.

I have 2010 office loaded on my PC, but for some reason it is saving the new file as 'MySlides.pptx.ppt' which is defaulting to 2007 format of '.ppt'. How can I specify what format of slides I would like to open and save the presentation as? Thanks

%HERE IS HOW I CALL THE CODE, SIMPLIFIED
filespec = 'MySlides.pptx';
ppt = actxserver('PowerPoint.Application');
op = invoke(ppt.Presentations,'Open',filespec,[],[],0);
%THEN MODIFY SLIDES...
%NOW SAVE
invoke(op,'SaveAs',filespec,1);

Answer 1

[Fangjun Jiang]

try invoke(op,'SaveAs',filespec,11); 11 is ppSaveAsDefault. Go to PowerPoint help, Visual Basic Reference, Enumerations, PpSaveAsFileType to see all the enumeration values.

[Kevin]

Excellent. Worked like a charm, thank you.

[Fangjun Jiang]

If that is the case, maybe invoke(op,'SaveAs',filespec) is sufficient.

Answer 2

[Tony]

You may effectively work with powerpoint files with to repair ppt file

http://www.repairppt.pptrepairtoolbox.com