Plug and Play ?

So recently picked up a DDJ400, liked the plug and play option. Downloaded Rekordbox and had a play around, set some tracks up and thought i'd plug the controller in.. unit lit up, powered and then went into what looked like a standby mode with blue Release Fx and Hot Cue buttons lit.. the unit then did nothing.. had a look for settings which just kept showing that everytime I booted Rekordbox up or plugged in the DDJ it changed the audio driver over... Im absolutely stumped.. Rekordbox works fine but does not seem to work with the controller.. Any help would be most appreciated..