Installed Karmic release candidate. Trying to play various media. Oops. Attempts to get plugins for Firefox failed but fortunately I know the magic trick:
sudo apt-get install ubuntu-restricted-extras
OK. But no sound to hear the media with. I seemed to fix the problem with two small changes under System>Preferences>Sound>Output. I changed the device for sound output from one option to the other (both labelled “Internal Audio Analogue Stereo”) AND the connector from “Amplifier” to “No amplifier”. No idea why those weren’t set correctly for my system from the get-go and no idea why they’re relevant – just grateful to be hearing sound :-). My soundcard is a Soundblaster Audigy 2.
BTW the command cat /proc/asound/card0/codec#* | grep Codec didn’t work for me as the only thing similar in the rough location was cat /proc/asound/card0/codec97#0/ …