I had a simuler issue back in 2008 using my mac for my graduate course. The solution was to convert all files to Quicktime (MOV) and Audio Interchangeable (AIF) Files.
Hello all, I am having the hardest time trying to solve this issue we are having with powerpoint for mac 2008. A teacher came to me expressing concern that none of her embedded audio files, (MP3s and M4a), or videos(M4Vs), would play in slideshow view when clicked, as they were actioned to do. They worked perfectly fine in 'normal' view when double clicked on. I took the package contents and placed them on a thumb drive, and attempted on multiple setups we have here to no avail. Everything works perfectly under Office 2011 however, but we use 2008 here at the school. Any suggestions would be helpful. Below is a link to a video showing an example of a basic creation and failure of embed sound to play in a slideshow. ThanksJonathan--
Technology TechnicianWindsor Southeast Supervisory Union