I have had a similar problem, the volume knob became unresponsive, although the unit did not freeze. It was set to such a low volume, that at first I thought there was another issue. The new meters in the output block were reading the signal though. I rebooted, the volume worked long enough for me to turn it up a little, to the point where it was audible. Then it happened again - stuck at that particular volume. Another reboot, and now seems ok....time will tell if all is alright