Deny out-of-stock orders dioesn't work

[RabbitZzZ]

Hello,

I use Prestashop 1.6.0.14

I have set the global setting of "Allow ordering of out-of-stock products" to NO,

but nevertheless product which get the quantity 0 while in somebadys cart they can be ordered and the customer just gets the message that the product is out of stock.

Each product is also set to "Deny orders" when out of stock in the product specific settings.

How can this be?

Thanks in advance!