DJM-850 as both Soundcard and MIDI Controller for Ableton Live

Hi, hopefully someone can help me with a problem that's riving me nuts.

I have a DJM-850 hooked up to a MacBook Pro via USB running OSX 10.7 Lion and Ableton Live 9.1.  Using Pioneer DJM-850 Setting Utility v1.0.0.

I'm using the DJM-850 as a midi controller and have mapped the physical line faders to virtual channel faders in Live, mapped the physical cue buttons to virtual cue buttons in Live.  I have also selected the DJM-850 as my soundcard (for input and output) in Live.  The MIDI side of things seems to be working nicely but I can't figure out the soundcard side of it.  My desire is pretty simple, I want my main outputs (Stereo pair 1&2) from Live to be routed directly to the Master Out on the DJM-850.  And I want my cue output from Live (mono output 3) to appear in the headphone output of the mixer.

At the moment, in the Setting Utility programme, I have all my inputs set to 'USB' and all my outputs set to 'None' (because none of the output options seem appropriate to this case).  Maybe this is the source of my problems but no matter what I set the inputs and outputs to in the Setting Utility, I don't seem to get the desired effect.

What I have is the main Live outputs appearing on mixer channel 1 and the Live cue output appearing on mixer channel 2.  Which isnt that surprising but it isnt what I want.  It's like I need the mixer to stop behaving like a mixer and start behaving like a MIDI controller and a separate soundcard.

I'd be so grateful if someone could help me.  I know there's some knowledgable people on here, that guy Pulse for example seems to be an absolute ninja with this stuff but I dunno how to get hold of him.  Pleeeease!  :)

Thanks in advance!