I started having this problem back when I went from XP to Vista with a gigabyte board. Then I picked up a creative card just to resolve it. I am using the spdif optical out on the card to a ZERO DAC reciever. The problem is that if there is no sound it powers the amp off. So the whole time its clicking on.... clicking off.. clicking on... etc. The Creative doesn't do this. This has happened on two boards now.. one with Vista and one with Win7. Anyone else run into this? Is it a power savings features or some way of trying to control hiss? I would like to ditch the creative card and its software and use the onboard if I could get it working.