No Audio Output from my Fast Track Solo Interface

I Just purchased this Fast track solo Interface...But am getting no sound thru my speakers. My keyboard and MPC sampler play fine so I know its not the speakers. I hear the audio thru my headphones but still not my speakers. I checked the audio output on my computer and its says Fast Track solo. I have the RCA cables connected 2 my small beringer mixer straight to my M audio speakers and I hear nothing. If anyone can help let me know please I have a project that needs to be done soon..:confused:

Thanks again

No Audio Output from my Fast Track Solo Interface