Reply to Traktor 3.4 tracks went crazy

Hey all,
I've just upgraded to Traktor 3.4, and when playing a gig recently I found that when I was bringing in a track, suddenly both tracks seemed to start skipping forward out of control. It seemed to come right after a few seconds, and I have not been able to replicate the problem since. I hope I have described this problem effectively.

I am using Traktor 3.4 on a Macbook Pro, with Audio 4DJ and VCI 100 controller. Has anyone else had this experience? It makes me very nervous.

Cheers,
Brent