I still get constant noise out of my analogue outs, however, as a bonus now I now get the same noise out of the USB!
Here's what it sounds like....
http://www.timothyallan.com/audio/timsvirus.mp3
it never shuts off, even after a reboot of everything. Looks like I need to go back a version as that only outputted the noise out of the analogue.
Edit: I should mention that I'm running this on a 12 core mac pro on 10.6.4