Scaling Video Up

I’ve got a video that the client wants embedded into their SWF and to scale with the browser proportionality. No problem, drop FLV on timeline, nest in clip and scale script based on stage size. The problem is on large monitors, once the video gets to a certain size … about 1200px wide etc, it stops scaling up in the browser. Now in the IDE this runs fine. I’m using SWFObject to do the liquid HTML. Any ideas if this is a limitation on Flash’s end or if it’s something with the stage or what? I have see full screen video on my 24" monitor so I kow this can be done. I’m just at a loss as to why it breaks in the browser. It doesn’t work on Mac Safari or FF.