I have a clean version newuploaded
zen-cart-v1.3.8a-full-fileset-12112007
installed except for two of the security patches.

security_patch_v138_20080919
security_patch_v138_20090619

I have not made any other changes or added any mods other than add a couple of products.

In the admin under configuration>product listing

Display Product Model
Display Product Quantity

I have both set to 0 but they are still showing up on the product page.

Also under configuration>stock

Check stock level
Subtract stock

Both set to false

Allow Checkout

Set to true

If the product quantity is set to zero I get the sold out image instead of the add to cart box.

Now this one I can easily fix by making the quantity larger than zero but it seems better to find out why it is not working first.

I did try searching but did not see find anything.

Thanks