Quote Originally Posted by DrByte View Post
Is that something your customers are likely to do? If so, why?
My guess is that customers make mistakes sometimes, so I did a test the only way I thought a customer could get it right. They most probably are likely to do this if this is how I managed to recreate the same problem. As for why they would do it, I have no clue.

I tried another way and it will not let me checkout if only one is in stock.
I went to a product, clicked on add to cart and then the cart page came up, on that page I clicked on continue shopping (which takes me back to the same product I just added)
I again clicked on add to cart and the cart page comes up - this time though it warns that there is not enough stock (because I now have 2) and if I click on checkout it just keeps coming up with the stock warning - so that WORKS.

It is obviously something to do with it being open in a new browser window while logged in - if the product is already in the cart and you open a page in a new browser window and add the exact same product to the cart in the new browser window it lets you check out with the same 2 items - could this have anything to do with sessions?