I do not know your sound card, therefore I can't say that it is, nor can I say that it is not. However, I seriously doubt it. I use a Sennheiser cordless head, which is capable of supporting up to 4 headsets at a time, but that is done by the headset transmitter, not the sound card. Frequently, plugging a headset into the front I/O will mute the speakers, so even if you connected one headset at the sound card, and one at the front I/O, you would have what you have already described, one working, the other not. If your sound card has an audio control center, you might explore it for a means to not have it mute the speakers, when a headset is installed, but whether that is there or not is anyone's guess.