@DIDI > I'm just curious as to why you want to control Traktor with your DJM-900?
Do you also have CDJ's or CD players to control Traktor with as well?
It would have to do with the mapping values you would be using. Something isn't set properly and since I've never bothered to control Traktor with my 900, it would be best to play around with it and try different values and techniques.