Issue with CDJ 900s - HID mode to Traktor on a Mac

Hi there guys,

I'm having serous issues when connecting my pair of 900s to Traktor on my Mac using the Pioneer HID mode.

I'd be very grateful if you could help me out. There is no hardware issue as I've swapped every part of my setup with a different part. My setup is two 900s connected via usb, using HID mode, to my macbook to (a legit, purchased version of traktor. All have latest firmware and software) and 900s connected to a mixer using RCAs.

It seems Traktor doesn't like outputting to the aggregate soundcard created by Pioneer's CDJ aggregator. Outputting to just one CDJ (so both track decks coming through one channel) works fine, but obviously as they come through one track deck I can't mix using my mixer (Bheringer DJX750), rather only internally using my trackpad in traktor, which is obviously not to a professional standard haha!

Here is a video to show the issue: ( https://www.dropbox.com/s/m55lsw47kp4qhym/2014-08-09%2020.30.32.mp4?dl=0)

Hope to hear any suggestions soon! Thanks in advance for your help.

Max