XONE:DB2 headphone cue problem: mix bleeding into cue when on full cue setting

[Mollifier]

I just bought a XONE DB2 mixer today. I have the following issue. Despite the fact that the headphone cue/mix knob is turned all the way to cue, I can still hear a bit of the mix coming through. This happens even when the headphone monitor volume is set quite low. Is this normal? Does anyone else have this problem?

[Mollifier]

I called American Musical and after having me run some tests, they decided that the mixer was faulty. They sent a replacement to the store I bought it from. I then returned my old mixer and picked up a new one. There is no headphone/cue problem with the new one.