I am trying to add captions to an .avi video file embedded in a PowerPoint. I have downloaded the STAMP add-in and have followed the instructions provided by Microsoft for captioning the video: click on the add caption button at the point where you want your caption to start, click on the end time button at the point where you want your caption to stop, type in the caption text, repeat as many times as necessary to complete all captions. Then I click create captions. When I look at the captioned video, the captions are all text boxes stacked on top of each other and they don't seem to recognize the start and stop times as the text never changes during the video. What am I doing wrong?