Traktor + XDJ Aero Only 2-channel soundcard available? why? help me.

Traktor + XDJ Aero Only 2-channel soundcard available
I have installed XDJ Aero driver on WIndows 8.1 according to this guide http://www.pioneerelectronics.com/ephox/StaticFiles/Manuals/DJ/XDJ-Aero%20Traktor%20Pro%202%20Guide.pdf
However, in Traktor preferences, I can't seem to find "PIONEER XDJ-AERO ASIO" device. There is "Line (PIONEER XDJ-AERO)" device in Traktor Audio Setup device list, but in Output routing I see that this device has only 2 channels available.
What should I do to get 4 output channels in Traktor?
My system: Dell 1tera, Windows 1 64-bit,
Traktor 2. + full version,
Aero driver v. 3.0 (I reproduced the problem with thes las driver available in pionner.com)
Would be very grateful for help.