Shadowbox needs to load a .js file for each media type you wish to use.  I was using .flv so I loaded the ’shadowbox-flv.js.’  That file returns:

return {
tag:        'object',
id:         this.id,
name:       this.id,
type:       'application/x-shockwave-flash',
data:       options.flvPlayer,
children:   [
{ tag: 'param', name: 'movie', value: options.flvPlayer },
{ tag: 'param', name: 'flashvars', value: flashvars.join('&') },
{ tag: 'param', name: 'allowfullscreen', value: 'true' }
],
height:     h, // new height includes controller
width:      w
};

What i did was change it so that instead of using ‘object’ to embed the video, I used ‘embed,’ and now it worked!! Simple.

here is what i changed:

return {
tag: 'embed',
id: this.id,
src: 'flvplayer.swf',
allowscriptaccess: 'true',
allowfullscreen: 'true',
flashvars:  flashvars.join('&'),
height:     h, // new height includes controller
width:      w
};
},

see it working here

I’ve learned that firefox has a bug dealing with object vs embed which in certain cases doesn’t allow the swf loader to function properly.  Specifying ‘autoplay’ seems to have an effect on this as well.  The firefox bug for this issue is here.

hopefully this bug will be fixed soon