Even though I had the Essential-codecs from http://mplayerhq.hu
installed, and FireFox's about
lugins showed correctly all the available formats as "enabled" for mplayer-plugin, the majority of clips simply would start loading and then showed "stopped" before playing a single frame.
So I temporarily removed the mplayer-plugin (yum remove) and let Helix handle all realaudio and realvideo clips.
Now if I open a (ra/rm) clip I get an error (e.g.):
Bad Transport (rtsp://streams.omroep.nl/tv/tros/2vandaag/bb.bulowmeacher.rm)
System has FC4 on it, kernel 2.6.17-1.2142_FC4, all packages updated yesterday.
Any ideas how to fix this?