We recently discovered a discrepancy in our product import file under the "Inventory" tab.
1) For people that subscribe to InventoryAdvisor® Multi-Channel Inventory, the 2 image columns in the import / export file are named "Image Small" and "Image Large"
2) For people that don't subscribe to InventoryAdvisor®, the 2 image columns in the import / export file are named "Image small" and "Image big"
We have now standardized the 2 cases and the column names are now always "Image Small" and "Image Large". If you do not subscribe to InventoryAdvisor, you will need to update your product import file headings to avoid getting import errors.