One track records to another

This applies to 2.0 and 3.0......

I have a completed mixdown I want to add keyboards to. I have an M-Audio Audiophile card and a midi keyboard connected by midi cable. Using Kontakt 3.0 to access the sounds. I don't want to record the keyboard as midi, just as the actual wave file.  Normally my input settings in Audition are M-Audio Delta AP Multi but in order to have the keyboard come through I have to change that track to M-Audio Delta AP Mon. Mixer. The keyboard records fine but the track also records the mixdown track as well so I don't end up with a separate keyboard track, just a mix of both. Any suggestions?

Thanks. 

Sorry, I don't look in this forum with any regularity and I guess you'll have worked round this by now. If you haven't............. the problem is with your soundcard and Windows rather than within Audition. The sound card is being used to do two jobs; create audio from your keyboard midi data and also play back the Audition output. There's no way the two audio streams can be kept separate. If the soundcard is producing keyboard sounds and playing back your mixdown track, they will both have to come out of the single (stereo) soundcard output. Do you have a second PC to use with the keyboard as a synth only?