Mplayerplug-in problem

Dear All, I would like to somehow make sure that my mplayerplug-in does not try to use the realplayer since it does not seem to work with it anyway. Is there a file to edit or some way to make sure just the linux native realplayer 8 works in Mozilla instead of the mplayerplug-in? I have Mozilla 1.6 and mplayerplug-in 1.2 as well as the latest crossover. The mplayerplug-in seems to open most videos just fine and my crossover seems to get the rest. Realplayer needs to just work by itself. I would like crossover to be able to use the realaudio then for what the linux realplayer cannot do. Can this be done and does anyone know how? Any help will be greatly appreciated. Thanks, Marcia