Attribute Combination not working

HI,
I configured attribute combination (size / color) for a product, to control stock for each combination. I didn't select "Allow out of stock" checkbox and I set 0 (zero) for quantity, but our store sells this item. Why it´s not working? Do I need to set anything else?

Check https://www.nopcommerce.com/boards/t/7798/product-variance.aspx

HI Eduardo,
Thanks for the tip. Now I can understando how it works and is running fine for me.