Out of Stock - cart problems

[calvinorr]

Basically my shop only sells a few items (craft items) and there is usually a bit of a rush from some regular buyers to purchase stuff. Having just transferred from Etsy to my own Prestashop I have come across a problem with the cart that I was dreading.

I have an product with 2 items in stock

It would appear that two people put the same item in their cart at the same time - however the first put one in her cart and the second put two in her cart. The first one checked out 12 seconds before the second one. Payment was taken for all three items even though I only have two available.

What I was hoping for is a cart that as soon as one item is added to it (before payment is taken) simultaneously reflects this in the availability of the item. So therefore the other customer could only have added 1 item

I have Allow ordering out-of-stock product: Yes


I appreciate this might be asking too much - anyone got any thoughts