Office viewer macro doesn't display .pptm files

Step to reproduces:

• Upload the attached .pptm file on a wiki page.
• Use the Office macro to display it: office reference="Testfile.pptm"/

Actual result: the viewer is not displayed, but plain text links are shown:
First page Back Continue Last page Text

• Continue link leads to the page /img1.html
• Last page link leads to the last page of the file (here /img2.html)
• Text link leads to a page /text0.html
  But these pages can't be found, so the document is not viewable.

Expected result: to have the viewer of the Powerpoint file displayed on the page, as the macro supports .ppt, etc files.

Workaround : the viewer appears simply by changing the file extension from pptm to pptx (at least on the files I tested)