Hi Waltrik!
Good question. I just tested with Traktor DJ Studio 3.1.3 and that version works perfectly with the pipeline.
In my version, the list of sound cards prefixes all names with "DS" to show that they’re DirectSound drivers. I don’t see this on your screenshot — I wonder what the difference is.
In your screenshot it shows that it thinks the Pipeline has 32 channels. This could be the problem — if Traktor really thinks the pipeline has 32 channels, and tries to allocate internal buffers to handle this many challenge, maybe something goes terribly wrong.
Can you try a different version of Traktor and see how it works?
It may be worth reporting this to Native Instruments themselves.
///Leif