[WBFAir]

Mine does this too and I have done quite a bit of modding to get the earpiece as load as I could so perhaps this is why I hear it more now.

Also I should mention that I am using a aftermarket dialer software program so I am not using the WM at all and it still does it so it must be something very deep in the system.

Having said all this though, personally I don't find it a problem but I suppose if I were trying to be completely stealthy about a call, I suppose it could be a give-a -way.