f4v Playback Issue / jwplayer

Hey everyone, thanks in advance for any help on this. We've recently installed fmss 3, and working with our first site with major streaming needs. I've decided to use jwplayer (longtailvideo.com) to playback content from the fmss, but am having playback issues with IE8. I'm using swfobject to embed, and here's the code:

     <script type="text/javascript">
     var so = new SWFObject('jwplayer.swf','mpl','600','366','9.0.0', 'expressInstall.swf');
     so.addParam('allowscriptaccess','always');
     so.addParam("bgcolor","#000000");
     so.addParam('allowfullscreen','true');
     so.addParam("wmode", "transparent");
     so.addVariable('file','video.f4v');
     so.addVariable('streamer','rtmp://ourdomain.com/application/');
     so.addVariable('image','image.jpg');
     so.addVariable('dock','false');
     so.addVariable('autostart','true');
     so.addVariable('bufferlength','5');
     so.useExpressInstall('/flash/expressInstall.swf');
     so.write('video');

I've checked with the folks that produce the player, and they think the issue is lack of metadata, but really don't know much about metadata and where to insert. Any thoughts?

Thanks,
Mark