I'm running version 1.3.7. And I noticed another post about my same problem, but don't understand how it was resolved. (subjuct: Config > Product Listing > Missing options 1.3.6 -inksale)

****Display Product Add to Cart Button (0=off; 1=on; 2=on with Qty Box per Product)
Do you want to display the Add to Cart Button?

NOTE: Turn OFF Display Multiple Products Qty Box Status to use Option 2 on with Qty Box per Product****

I don't have the option 2=on, only 0=off and 1=on.