All this afte rupgrading from 1.4.1
I get a quite specific error message:
Next exception \'Zend_Db_Statement_Exception\' with message \'SQLSTA
@perler, here is a MySQL query to detect duplicate SKUs. Remember, if you prefixed your tables, change catalog_product_entity accordingly!
catalog_product_entity
SELECT DISTINCT(`sku`) as `sku`, COUNT(`sku`) as `skuCount`, entity_id FROM catalog_product_entity GROUP BY `sku` HAVING `skuCount` > 1;