In the file woocommerce-osc-sync.php in line 557 change this
if ($ orders = $ oscdb-> get_results ("SELECT * FROM orders ORDER BY orders_id", ARRAY_A)) {
by
if ($ orders = $ oscdb-> get_results ("SELECT * FROM orders ORDER BY orders_id DESC", ARRAY_A)) {
When I have time I made the change so that the plugin has it by default
regards
