signiatech

Hello all, I am facing an issue with my prestashop and i was hoping someone has found a work around to it. I manually changed the position in category for all my products on my shop. I use webservice to upload products information, and when I do that, the position in category for the products updated becomes 1 for all of the categories it is on. The only case it does not happen, is when updating the stock, then the position in category doesn´t change. Anyone can help? Thanks in advance.