HELP! Audio/video won't play in PowerPoint Broadcast!

Audio/video objects embedded in, or linked to, a PowerPoint 2003 slide show supposedly won't play when viewed in a web browser, unless the slide show is saved as a PowerPoint Broadcast (or created via PowerPoint Producer).

They actually DO play for me when my slide show is saved on a local drive as a multifile webpage (even if it wasn't created via Producer). (Incidentally, because this works for me only for multifile webpages and not single file webpages, this means that audio/video objects are linked to, rather than embedded in, my slide show, just as they are in a PowerPoint Broadcast.)

But audio/video objects WON'T play for me when my slide show is saved as a PowerPoint Broadcast. This is so even when the slide show resides on a local drive, so it's not a matter of needing Windows Media Services installed (which is unnecessary for PowerPoint Broadcasts to ten or fewer simultaneous viewers anyway).

Does anyone have any idea why the audio/video won't play in my PowerPoint Broadcast?