Out of Stock issue

[split63]

When a product is out of stock, we want to continue to allow customers to order and their orders become back orders.

We have set the Store Config/Stock and the individual Catalog/Product settings and its working, but under the Catalog/Product page for the item, there is a field which allows the entry of the anticipated "Date Available". This does not show up on the product page which is out of stock. If I set the "Out of Stock" radio button on that same page, then the product page itself disappears on the the site. This is despite having the following settings under Configuration --> Stock

Check stock level : False (this seems to do nothing)
Subtract Stock: true
Allow Checkout: True
Mark Product out of stock: No Stock
Product status in Catalog when out of stock should be set to: 1
Show Sold out Image: 0 (No)

During the preview for the product page, the "Date Available" message shows correctly, but not on the actual page.
I'm using version v1.3.9e