I am having problems playing .rm files (new southpark episode) on My N73,
RealPlayer says "unable to play either sound or video" then it just plays the audio.

I have a couple of full length movies in .rm format that play perfectly, so as far as I can tell it should work, but it dont!!

I have tried the Super-c conversion but keep getting error message when I click encode.

Any ideas???

Check http://forum.nokia.com/video (the format tables linked to on that page) for what format, resolution, etc., video files must have in order to work on the N73.

Then adjust the SUPER settings accordingly. If it doesn't work, it would be helpful if you stated what error message or messages you get (word for word, exactly as displayed).