I noticed this just today, but whenever an audio file is played, there's an audible "click" right before it begins playing. Similar to the sound of one of those bbq lighters. I thought it was just using iTunes, but that's not the case, as when the audio file for "logging in" or "logging out" is played in iChat, it does the same. I then proceeded to change headphones, from my Bose QC2's, to a pair of ipod headphones i had lying around. Same noise. So it's obviously Mac-side and not headphones or apps. I didn't notice this before, but I didn't use my headphones much until just the last day or so, since it is a new computer. I also have Boot Camp installed, and so I have the new firmware. I'm thinking maybe some of the audio problem is caused by having it flashed with the new firmware that is also Windows compatible? I'm thinking this because of the fact the headphone port glows red when in windows, since you can't use headphones and have the speakers off, as of yet while in Windows XP. I'm thinking about reinstalling OSX, but I don't think that reflashes the firmware. Is there anyway to get the old firmware again? I might just erase the XP partition, and use an old crap windoze box, just to save the trouble of the annoying audio. The mobo whine was annoying, the click is just rediculous. I have a feeling I'll be paying a visit to the Apple store tomorrow with my receipt. Any thoughts?