I tried booting off of my 10.04 live usb, and the problem is still there.
I just downloaded the 9.10 live cd and will give that a try next. I am almost totally positive that it will work just fine with 9.10.
EDIT: I gave it all a go with a 9.10 live usb and I got the same result: The mic is still not working. I find this very odd, as I am positive that I have had it working at some point in time under Ubuntu.
Can anyone else give it a go and report on your findings. I'd like to know, at the very least, if I am alone in this or not.