I'm using Dapper and I didn't initally get sound either.
Here's what I did:
sudo chown root:audio /dev/dsp
sudo chmod g+w root:audio /dev/dsp
Now getting that to work in TS2 is a different story, I think I've finally got things figured out sound-wise on my system. Let me know if you don't have /dev/dsp on your system, we may need to install the alsa oss emulation packages.
Good luck.