In orders.php you should have:
a href="' . tep_href_link(FILENAME_ORDERS_USPS_SHIP, 'oID=' . $HTTP_GET_VARS['oID']) . '" TARGET="_blank">' .
Change it to:
a href="' . tep_href_link('uspslabelfix.php', 'oID=' . $HTTP_GET_VARS['oID']) . '" TARGET="_blank">' .
then just upload the new uspslabelfix file i made