If you store Gallery Images in a Non-Web Accessible location, and upload a Media file, Flowplayer will fail to load.
My guess would be because of the URL used to point to the Video. It's being double encoded, so & in the URL turns into &
This is n the source when set to Non-Web Accessible:
<script language="JavaScript">
ipb.gallery.flashPlayerInit( "http://localhost/ipb_stock/index.php?app=gallery&module=images&section=img_ctrl&img=1&file=mediafull", "http://localhost/ipb_stock/public/flowplayer/flowplayer-3.2.7.swf" );
</script>