Hmmm....
So is there no way to get a new Office 2008 ppsx file to display correctly to a Mediawiki user?
What I want to do is have my internal users click on the ppsx link and have it recognize it correctly and not as a text file.
The code changes I mentioned work for me (because I'm using img_auth.php). I'm not sure how to fix the problem if your files are being handed out by Apache.
V/r,
Ryan Lane