DDJ-RR midi mapping to mixvibes

Hi, I am trying to midi map the DDJ-RR to latest version of Mixvibes Cross 3.4.3 (using 2012 MacBook Pro) using the mapping section in software preferences and although it seems to map OK , the controllers in the software, i.e. on the screen are jittery and don't react properly when moving the slider and knobs on the DDJ-RR.

A DDJ-RR controller tab shows in Cross preferences and I have created a DDJ-RR controller mapping to map to and it appears relatively straightforward; Add mapping, select master volume (for example) move the knob, hit OK and it does map, but the visual display on the screen goes bonkers and moves all over the place !! 

It's the same for all the mappings, pitch, crossfader, effects....any advice anyone??

Cheers,

Steve Shorter

PS I have all up to date firmware etc.