Selling Out of stock items

Typically when you click in the qty block after adding the item, it will tell you the stock level.

As I remember only enterprise has a preference setting to not allow OOS items to be sold, but check your preferences for this kind of setting

Problem is i used to have it till now. I used to get this pop up box, when i tried adding OOS to a sale, saying "You have insufficient qty of this item are you sure you want to add this item?"

but then it stopped. Now i can just add it to sale no problem i dono what changed. And its really annoying not knowing what your selling if you got it or not..