We're using Magento 1.7.0.2 for over the counter sales in a pharmacy, and because we update our Magento inventory once a week with new products & stock updates, many times we receive stock which is lying and ready for sale, but Magento has not yet been updated.
For this reason, I need to be able to sell out-of-stock goods from the Magento front-end.
I have tried enabling backorders (System >> Configuration >> Catalog >> Inventory >> Backorders >> Allow QTY below 0
But in spite of setting this, the front-end still shows (products with zero or negative as) out-of-stock and thus cannot be added to cart.
I have even flushed the cache and reindexed everything but no luck.