No ability to monitor the cue track with U-Mix Control Pro

Hello. I've been using the U-Mix Control Pro controller in conjunction with the Cross DJ 2.0.1 software. I have been unable to get the monitor function to work properly with my headphones and set-up. I am using a two speaker set-up with one amp, my laptop, and the U-Mix Control Pro unit. In the middle of playing a track on the first deck, I would like the ability (as many DJs do) to monitor the next track on the second deck and cue it to a suitable position. However, I cannot figure out how to get this function to work. With my headphones plugged in, any change in the volume level for the "Mix" or "Level" for the headphone input seems to make the cued track play on the main speakers as well as within my headphones (as opposed to just within the headphones). I also have the headphone source button selected for the cue track as well (the button near the Gain knob).
I have played around a bit with the Audio tab in Settings, but nothing seems to make this "monitor" function work properly. The standard/default selection for my setting (or the one that works best) is the MIXVIBES ASIO U-Mix Control Pro. I read an older thread on here where someone had a similar problem and it was suggested that perhaps the audio driver was incorrect or something to do with the input/output settings in the Audio tab.
I am running Windows 7 SP1 64 bit btw. Any help or suggestion would be greatly appreciated.
Thanks!
I have played around a bit with the Audio tab in Settings, but nothing seems to make this "monitor" function work properly. The standard/default selection for my setting (or the one that works best) is the MIXVIBES ASIO U-Mix Control Pro. I read an older thread on here where someone had a similar problem and it was suggested that perhaps the audio driver was incorrect or something to do with the input/output settings in the Audio tab.
I am running Windows 7 SP1 64 bit btw. Any help or suggestion would be greatly appreciated.
Thanks!