I missed that thread - thanks for the pointer. So I'm not confused, are you running the DAC off of the Pi - or is it connected to another computer (I got a little mixed up following).
If on the Pi, did you have any USB issues (I'm using the Adafruit Occidentalis 0.2 distro)?
I may try to use a DAC - but have to spend a little time figuring out how to get the sound to come out the USB port, when I did the other project (Raspyfi) it was already set up to use the USB port if a DAC was connected.
Rich