Calculation error in Turbotax Desktop? On Form T2125 I have a negative number on line 8158 (Cost of Goods) and it is being added to income 3P instead of subtracted.

Isn't the program supposed to subtract 8158 from 3P to make the number on line 8159? Because there is a minus sign in front of my number on 8158, it is adding it. (a number minus a negative number = addition).