Purchases of inventory items amount 0.00

Hi, i’m doing a pre order business,
so i will create a sales invoice when i received order.
then only create a purchase invoice.

sales invoice created on 26/6/14
purchases invoice created the day after it.
the amount of purchases of inventory items for that transaction will show 0.00

but if i change the purchases invoice date to the date before sale invoice, it showing correct amount.

This is anomaly when selling inventory items while having none on stock. In this case, Manager is unable to determine cost of goods sold and therefore no amount is posted to expenses.

I’m planning to improve inventory to handle this edge-case a bit smarter. For example, if purchasing inventory items while quantity on hand is negative, Manager will immediately post relevant amount to expenses upon purchase.

yes, please. i really need it.