I've had a Zero DAC for two years now and it's been great for my modest needs. Previously, I had it hooked up to my 20" first-gen Intel iMac and it worked like a charm. However, I've recently noticed that on my new 27" iMac, after a relatively short period of inactivity, the Zero DAC clicks off and then has to click back on for the next sound event. It's a bit annoying and I never had this problem with the 20" iMac. Reading various posts it sounds like this has been fixed with better drivers in some Windows based setups. Anyone run into this on a Mac and find a way to fix it?