However, instead of fully opening, the word "Loading..." shows and nothing else happens:
If anyone's got a fix, please share.
For the time being, here's a workaround using a slightly different method:
Click to open the Powerpoint file you wish to download:
Click on "Menu" on the lower, right corner:
Click on the File name:
When the presentation comes up, click on "Actions" then "Download as PPT"
Like I say, if anyone's got a better method, please pass it along.