imitone community

I've just today started using imitone (0.5.3), but it seems to be having a lot of trouble detecting low notes - like anything below middle C, it just doesn't pick up at all.  Unfortunately, that's the natural range of my voice. :)  Whistling, and singing higher notes seem to work pretty well, but the lower stuff is just not coming through.

I've tried pulling down the Minimum Loudness slider all the way to the bottom, but it doesn't improve things.

I recorded a capture file: capture.wav. imitone didn't pick up even one single note when I sang this.  But when I listen to the file it sounds perfectly audible - the mic is working fine.

I notice there is some low-frequency noise, maybe that's confusing imitone?  Also, I am not a trained singer at all (as you can no doubt hear in my capture file :)), so maybe I'm not able to maintain a consistent enough pitch for imitone to detect a note?

I'm working on Windows, using a Logitech ClearChat headset mic.

Thanks.