Whenever I try to play an embedded wmp video with firefox (and internet explorer) it shows up but the video area is black, and only the play button is clickable but nothing happens when I click it. This only happens on some sites such as stupidvideos.com. I have all the plugins such as active-x, wmp plugins and windows media player is installed on my pc. I've tried reinstalling everything but that didn't work. Can anybody help me?