Pioneer DJM 2000 NEXUS

Hi everyone i recently bought a Pioneer 2000 Nexus mixer and i am trying to use the built in soundcard instead of my Mixvibes external soundcard.
I am not using the mixer with CDJ'S but Technics 1210's with mixvibes time coded vinyl.
When i plug the lead into the USB port in the mixer and the computer and then start mixvibes i go to the preferences then audio section and it is not showing as available to choose as the source.
The computer has registered the mixer as it recognised the mixer when i plugged in the usb lead and and told me it was ready to use.
My aim is to use the mixers soundcard and then map it to mixvibes so if anyone can help with the mapping for just the DJM 2000 NEXUS with mixvibes i would be most greatefull.
I am running windows 2007 vista
Many thanks
Dave
I am not using the mixer with CDJ'S but Technics 1210's with mixvibes time coded vinyl.
When i plug the lead into the USB port in the mixer and the computer and then start mixvibes i go to the preferences then audio section and it is not showing as available to choose as the source.
The computer has registered the mixer as it recognised the mixer when i plugged in the usb lead and and told me it was ready to use.
My aim is to use the mixers soundcard and then map it to mixvibes so if anyone can help with the mapping for just the DJM 2000 NEXUS with mixvibes i would be most greatefull.
I am running windows 2007 vista
Many thanks
Dave