Videos inserted into PowerPoint 2004 plays audio, no video

A movie file that I inserted into a slide plays audio but no video when in Slide Show mode. The video clip will play perfectly well previewing it during the building of the presentation, and it plays fine outside of PowerPoint. Interestingly enough, the whole set-up works on another computer so it's not a built-in defect of PowerPoint. <br><br>The format of the video clip doesn't matter: MOV, AVI, MPG. Installed on the computer have been QuickTime 7.0.4, 7.2, and 7.3.1 -- no changes. <br><br>OS 10.4.11; Office 2004 11.3.9; QT 7.3.1 <br><br>I've installed Flip4Mac, VLC, the DivX codec and the Xvid codec at various points and none of them made a difference. I can't compare the two computers and the differences between the two because the one computer that the embedded movie works on is running Leopard, rather than Tiger.