Reply to Kontrol S4 + Traktor Duo?

Somone told me i could have Traktor Pro 2 and Traktor Scratch Duo 2 installed on the same time on my macbook, but that's wrong .. so now i own one license with TP2 and one with TSD2, so .. can i use the S4 in duo? I can't get it to work.

Or do i have to enter my serial each time in Service center untill i get TSP2?

Thanks.