Reply to S2 not working

Hi, I recently sold my kontrol S2 via ebay and the provided traktor pro 2 software to someone else. I never registered either to myself. The guy who bought Traktor is not having any problems but the guy who bought the S2 can't get it to work. Apparently the USB light turns on and the computer recognizes the S2 soundcard option within Traktor but when he chooses, the S2 doesn't kick on.
I believe ultimately he wants to use it as a midi device for another program.
Is it possible that the S2 wont turn on because the traktor registration that was provided with the S2 is already registered to someone else (the guy I sold Traktor to)? Is this some kind of protection scheme that NI uses?

He has uninstalled the drivers and correctly installed them a couple times.

Any clue what is going on? thanks for your help.