Another issue I have found is this: the headphone volume switch has a position beyond zero volume where it seems to click to an off position. Why this is I don’t know. But when in this position, i.e. clicked to off I get strange behaviour when using the BB normally. What happens is that on pressing the main foot pedal on the BB a number of times quickly in succession, as in when trying to trigger an outro, the display shows the headphone volume setting. In fact it initially appears as set to a value around 9 and quickly counts down to 0. Very strange.
If you turn the headphone volume dial out of the off position (you hear a clicking sound) but leave the volume at any level then the problem appears to go away.