Hello! I have an item on a sales order with quantity On hand = 4. The SO state 5 in quantity for the item. We use the fulfillment request record to make sure we only can fulfill what's in stock. A fulfillment request has been created for the 4 like i wish. But then we noticed that its possible to create another Fulfillment request for the back ordered quantity. How is this possible when i don't have stock levels to cover this fulfillment request? is this a setting that i have missed?

This was a while ago so you've probably already figured this out, but I would check in your accounting preferences: