Fedora :: Firefox Not Opening Mplayer Fc11?

i used to be able to watch music videos from a local radio station website using firefox and mplayer with fc11. maybe the solution is to upgrade to fc12, since it seems to work fine on the pc with fc12, but maybe the problem is something easy to fix, and i can wait awhile before getting everything up on fc12.. -( also, with fc11, i can play the same videos using a newly installed version of google chrome. i am just trying to find out what causes this type of error and how i can fix it. if i go to www.kzsn.com and select the "on demand" tab, then select a video, i should see mplayer open up and the video play - i don't get the black box and no video, no sound.. as stated above, this works fine using google chrome, or using another pc with fc12. this website also has some videos that play via flashplayer. they also did not play in fc11 with firefox, but i was recently able to get them to work by downgrading to a previous version of shockwave (found that in another post). not sure if this has anything to do with the problem i am having, but thought i would mention it, just in case.. only other thing i can't seem to do with any release of fc (maybe linux in general) is watch movie trailers from the apple website (which used to work fine) - was wondering if anyone else can with fc11 or fc12?