video playback only works when hardcoded

so, I am able to obtain playback when I create an HTML page with no scripting involved to play a video file.

when I try to generate the exact same file using PHP or javascript the video does not play. the error I get is "the downloaded video is not a divx file"

the server runs
apache 2.2
php 5
ubuntu 9.04

I even tried modifying the multiple.html sample to play my video, but I get the same error.

I can't seem to post php or html code into this without it trying to execute it. I'll see about uploaded the code to some public website somewhere.