Datel Gaming headset

Question

I plugged the device into the PS3 and setting is set for input & output to C-Media USB audio device and I hear no sound coming out of the TV, but when I change the output setting to system default I can hear my voice on the TV but once i go online it does not work. So as per the instruction input & out should be set as C-Media USB audio and that does not work. Any ideas? Thx