When exporting a PDF from PowerPoint (I use PowerPoint 2010), each image that was inserted into the PowerPoint document from a file will have a tooltip showing the file name in the PDF. I didn't even know before that PDF elements can have tooltips. It is very annoying an distracting when the tooltips come up during a talk.
Question: How can I prevent the tooltips from being included in the PDF?
Note: Using alternate PDF viewers or alternate settings in Adobe Reader is not an option.