I got a new external USB soundcard. It's a Turtle Beach Audio Advantage Micro II. It was a simple plug-and-play thing. I'm using Windows 7. The moment I plugged it in, Windows recognized it and i could hear the music. I was able to change the volume and everything. Then i clicked on a few settings or so and now I can't change the volume. I can see the icon in the system tray and i get a volume slider but scrolling the volume slider doesn't change the volume. I can't even mute the darned thing. Any ideas on what could be wrong?