Item Purchase Order Receipt Problem

Hi, Most of the time my inventory items post properly to the GL upon PO receipt. However I have one inventory item that only posts to the GL when the invoice is processed (vouched). In otherwords, the item quantity posts to the inventory but the financial posting only happens later when the invoice is processed against the PO. If someone has experience with this problem and a solution, I will be most grateful. Thanks.

For that particular item, check the item model group. Probably Post physical inventory is unchecked.