Has anyone seen a situation where the mic signal varies crazily from day to day?

Like, yesterday, dictation worked beautifully. Today, same hardware, same software config, it's terrible. Hopeless.

I tried rechecking the mic levels (accuracy wizard) and that made it even worse! I also tried making a new user profile and the training wizard wouldn't even recognize when I said "Welcome." (That's with a pro-grade audio mic through a pro-grade usb audio interface. DNS reports a sig-to-noise ratio of 31, better than I ever got with a headset, but it's still total fail.)

Really strange...

I admit, I'm on a weird configuration (ubuntu 10.04, realtime kernel, jack --> pulseaudio --> virtualbox running xp and DNS) but it has been working beautifully until just recently.

Just wondering... if nobody has any ideas how to cope with this, I'll keep messing around with it. Next step... reboot I guess.

TIA,
James