Your menu not showing up in IE6 is because IE6 doesn’t recognize the :hover pseudoclass on anything except the <a> element. You’re using it on <li>'s to allow for block level drop downs. You can use jQuery to fix that.
It seems that wmode isn’t one of the supported options for quicktime which is why some browsers support it and some don’t. I can get your movie working in all but not all at the same time.
I suggest you convert the movie to flash and then it will work everywhere.
Your dropdown menu was working in Ie6 when I checked and will overlap the menu if you add the <param name=“wmode” value=“transparent”>. Safari need wmode=“transparent” in the embed tag but that’s what kills Firefox (actually Firefox works but only on odd pixels as you close or open the window).