First off you will never get it to work if you do not meet the minimum demands by Traktor
http://www.native-instruments.com/#/en/products/dj/traktor-pro-2/?page=2050
You need at least 2Gb of ram for start.
I suppose you have a PC not a Mac?
If PC you need to turn everything off and if you use Vista you ask for problems and should try Win 7
Or at least you need to reinstall of the Vista.
also you need to turn everything that is not needed for DJing on your laptop off.
After that you should try to raise the latency settings in Traktor settings.
If you still have problems there is a risk that your laptop does not face the standard in the USB outputs.
That problem Pioneer DJ ergo suffers from and in that case you need to get a POWERED USB hub
so that your soundcard gets the power in the USB port that it needs…..
//DJ Hessler