mike mystery

I fly online with a plugged in mike and two loudspeakers. I never had a problem with either.Recently my mike is not working. I can hear the controller, but have to type back my response-very annoying.I tried to callibrate the mike in the SB options/ voice section. The result is negative; I get a report that background noise...mike quality...replace the mike.. bla bla.Yet, when I use Skype the same mike works perfectly. It's placed on the desk, a good 50 cms away, and picks up my voice. Within SB, the mike is useless.I've got max volume within the windows sound manager.So what is exactly is the problem?Eytan Ornstein