Many if not most of us need to view Real Audio files on the web. RTÉ, the main Irish tv station, uses it extensively, for example.
I had installed the open source Helix Player from Add/Remove Applications - or maybe it was already installed, I’m not sure. But that didn’t work for the RTÉ media. I [...]

Totem could not play ‘dvd:///media/cdrom0′.
Problem: when you install Ubuntu, the default player Totem will not play dvds. It requires that certain codecs be installed. The forum linked to below solves this problem.
The solution is at Linux Forums. Thank you ‘antidrugue’ at Linux Forums
update
New codec problem with Totem
requires
MPEG 1 Layer 3 CBR
Solved January [...]