All PC sounds to 11R

I'm trying to setup my eleven rack as my PC's main soundcard. I'm using Windows 7 and have set the Eleven Rack as my default device. I have two studio monitors plugged in to the "output to amp" jacks in the eleven rack's front and back. The problem is that I can't hear any PC sounds from the monitors. If I plug one of the monitors to the "phones" jack, I suddenly get all my PC sounds from one monitor bot obviously no stereo. I've tried messing around with the eleven rack's settings, and even resetting to default without any progress... Do I have to plug my monitors via XLR in order to get this to work or what?