Is that how you have it set in the Stock settings?
Note: Changing this setting to take the Product to products_status = 0 will not occure unless the Product is checked out and then during the checkout_process the stock falls to < 1 or 0 ...
If you just set the products_quantity to 0 you need to manually set the products_status to 0 ...
If you need to update you database to have all products_quantity <= 0 set to products_status 0 then you could run a SQL command to do this for you ...
First backup your database ...
Did you back up your database?
Next, in your Zen Cart Admin ... Tools ... Insert SQL Patch ...
You can type in:
PHP Code:
UPDATE products SET products_status=0 where products_quantity <=0;
This will take all Products with products_quantity <= 0 out of stock and hide them from the Catalog ...
NOTE: Backup your database first ...