This fix was harder to find that it probably should have been, so I’ll reiterate…

The Problem : The headphone / earphone jack is being ignored by Ubuntu 8.04 (‘Hardy Heron’) on the Sony Vaio VGN-FZ21S. Sound continues to play exclusively through the lap-top speakers whether or not headphones or earphones are plugged in.

The Solution :

Edit the file :

/etc/modprobe.d/alsa-base

To include this line at the end :

options snd-hda-intel model=vaio

Save the file and reboot your machine.

Mad props to these guys for providing me with the solution. And this fix should also work in Ubuntu 7.10.

Now I can get back to Battlestar Galactica, without pissing off the neighbours :)