From Phil @ NI forums -

Here the deal. I need to hear from people running on a mac that are having Timecode problems or have problems with Pops Clicks and Dropouts. This is a simple fix that simply involves creating a brand new user account. Load nothing at startup and run Traktor in the bare new user environment. Let me know what your results look like.

My McBook Pro worked great until about 3 weeks ago and I was having no problems with dropouts then after having a problem where none of my NI gear was being detected in the O/S I could reproduce all of the same problems people were reporting here. Last weekend on a whim I created a new user account that had zero addons starting at login, and just like that I got near perfect operation. I tested on a second system that was having problems last night and it too cleaned up immediately.

What I want to do now is verify with others that this solution works with others. All I did was to create a new user account in system preferences (I made mine an Admin) turned on quick user switching and switched to that user. Without doing anything else I ran Traktor and tested the system. I've run Timecode Hard and found the system worked beautifully. The problem with FX Dropouts when FX is enabled still lives on but that can be worked around.

Please test it out and let me know your results. I'm trying to find out what is causing the problem in my regular user account and will report back when I have more details. In the meantime, Two for two fixed is a good result. Lets see if we can boost the odds.