I been having this issue since the beggining, but just now i discover what it is. When a client make click to the checkout and goes to paypal, there is a link that reads: "cancel and return..." guess most of the clients would make click on that button if they want to cancel, but there are some clients that close the paypal page, and when they do that, hikashop take away from the stock the products of client´s cart as he buyed, but he didnt buyed, he just close the page.
This is very strange, because if you check the sistem, you can see that the system cancelled the order, but still, the products are reduced from the stock, why the system do that? I dont know, but it happens always someone just close the paypal page.
Is any way to solve this?
I appologize for my english, if you have any doubt about this problem please let me know and i will try to explain better.