Sorry guys, i never knew about this till Dread old me.
I found the solution, but not the cause - went to the volume control panel, then Properties -> Recording, and lowered the microphone volume. After that, SF4 doesnt see the mic as being on any more, althought i still dont know why it thinks its on in the first place if it isnt even plugged in!!
I found the solution, but not the cause - went to the volume control panel, then Properties -> Recording, and lowered the microphone volume. After that, SF4 doesnt see the mic as being on any more, althought i still dont know why it thinks its on in the first place if it isnt even plugged in!!