I have products that often need updated descriptions and prices. I do this via dataflow profiles import, using a CSV file edited in openoffice.
Sometimes when I import a CSV, it updates the 4000 products with the SKUs from the CSV with the updated description and price, which is great!
Sometimes when I import a CSV, it creates 4000 NEW products. These will all be DUPLICATES, with the same SKU as the old product, but the new description and price. This is awful, because I will then have to delete all of the old products.
What is confusing - I will use the SAME CSV from last time, and do nothing but edit the price and description fields. Why is magento creating new products if I am using the same SKU? I thought the entire point of the SKU attribute was that two products could not have the same SKU.
I have not been able to narrow down what makes certain CSV files revise products, and what makes other CSVs I have create new products. I edit them in notepad++, some have different placement of quotes, but I cannot narrow down what exactly triggers Magento to create new products instead of update the attributes of the products already in the database with an identical SKU to the products in my CSV.