title: Magento Product's url_key get being overwritten
body: <p>I maintain a large catalog of products in a Magento store, mostly through magento's API calls.</p>
  
  <p>When I add products to the store I add them with a url_key like <code>manufacturer-sku</code> which means the product is reachable at <code>www.domain.com/manufacturer-sku.html</code>.  However, after some time the products end up changing their url_key to be the product's name, which means the product resides at <code>www.domain.com/sku-some-words-that-describe-the-product.html</code></p>
  
  <p>Why does this keep happening? And how can I stop it from happening?</p>