If you save a Powerpoint as a "PowerPoint Show" (or PPSX) file, and open it from your desktop, it will open in Powerpoint slide show mode. The viewer cannot alter it or save another copy.
If you take the SAME PPSX file and load it to Beehive, and then click on it, you get the choices of OPEN or SAVE. If you OPEN it, it does NOT open in Powerpoint slide show mode, but instead it opens in REGULAR Powerpoint as a "read-only" with FULL rights to SAVE-AS under a different name.
This completely defeats the purpose of trying to share a presentation with a non-Oracle "group" when the presentation is best seen as a slide show, and not seen simply as a "flat" PDF file created through "print to PDF".
beehive knows nothing about the file extension and is only directing it to a helper app to open - I suspect this may bthe briowser/app combination that is opening the file and then offering to save as another file.
It may be that the explorer has some MS hooks in it to make the ppsx file open in slideshow mode.