VCO1 of the fifth voice on my PolyBrute is running on a very low constant frequency only, lower than the other oscillators can be setup to run. None of the controls seems to have any effect on it's frequency, pressed key, pitch knob, pitch bend, or midi note. I've ran calibration routines multiple times, reinstalled the firmware, and reset settings and tuning calibration to factory state. I bought the PolyBrute about two months ago and this problem occured just today. Has anyone else had similar problems?