Thanks for the reply. I submitted a ticket as reccomended. The line has something to do with the strength and length of the Puff. The stronger and longer it is, the more the line moves to the left of the displayed graph. If the puff is ever so slight, the line does not display. Go a little longer and stronger, and the line just starts to appear at the right edge of the graph. Go even a little longer and stronger, and it moves a little more to the left. That is the only correlation I’ve been able to determine.