I've been using the Microsoft Lifechat headsets for about 4 years now with no problems at all. Recently I started getting complaints from online friends about a horrible noise in the background when I talk. I tried a new usb headset and got the same problem. I tried every usb jack on my computer with the same result. The noise is like a series of square waves changing frequency randomly. It occurs in all applications that use the microphone. The audio output works fine. Is this a problem with the onboard sound processor or the usb drives, or something else?