DMJ 2000 Nexus with CDJ 2000 Nexus 2 & Rekordbox problem

Hi,

Im new to this CDJ business (Xmas Present) a new level to my Technics 1210's.  Right I've got the DMJ 2000 Nexus Mixer, connected to both CDJ 2000 Nexus 2's via phone cables, I also have the ethernet cables connected to channels 2 and 3 of the mixer.  I then have the mixer connected via USB and Ethernet directly into my iMac.

I have been able to get Rekordbox to work with the mixer directly in performance mode, however nothing in rekordbox is visible on my 2 CDJ's?  Looking at Tutorial videos it appears there should be a link button on the bottom of the Rekordbox screen, however this is not appearing?  Its version 5.0.3 of Rekordbox.

Any ideas?  As currently I've got a really expensive set of pretty lights and thats it.

Thanks

Darren