Some sound card drivers will mute the input to prevent feedback whenever you start recording, so you may have to unmute it again after recording starts.
Where I found this to drive an owner nuts is when they had Vista's voice recognition turned on and that nice interplay of voice recognition and drivers did this.
Sorry I have no exact fix but we disabled the voice system and the issue vanished.
Hope that's it.
Hello. I have Vista running on a Lenovo 3000 N100 laptop. It has been set up and running for several months now with 0 problems. Recently I downloaded Quicktime / iTunes combo to play m4a files from my iTunes on my XP machine at home. That's the only change it has had. SO... I'll be working on something and the volume box will pop up (the smaller one) and it will mute. I will unmute it and it will pop up again muted. Eventually it will sit there and mute and then unmute and then mute, and so on... by itself.
I tried googling this, but no luck. Has anyone else heard of this.