I have no recolection of doing such a thing... Here are my results...
catalog/admin/includes/languages/english/paypal.php
Line #29 : define('TEXT_SORT_ZEN_ORDER_ID_DESC', 'Order ID (high - low), PayPal Order Received');
Line #30 : define('TEXT_SORT_ZEN_ORDER_ID', 'Order ID (low - high), PayPal Order Received');
catalog/admin/paypal.php
Line #14 : array('id' => '2', 'text' => TEXT_SORT_ZEN_ORDER_ID_DESC),
Line #15 : array('id' => '3', 'text'=> TEXT_SORT_ZEN_ORDER_ID),
catalog/includes/modules/payment/linkpoint_api.php
Line #531 : if ($sniffer->field_exists(TABLE_LINKPOINT_API, 'zen_order_id')) $db->Execute("ALTER TABLE " . TABLE_LINKPOINT_API . " CHANGE COLUMN zen_order_id order_id int(11) NOT NULL default '0'");
Line #601 : if ($sniffer->field_exists(TABLE_LINKPOINT_API, 'zen_order_id')) $db->Execute("ALTER TABLE " . TABLE_LINKPOINT_API . " CHANGE COLUMN zen_order_id order_id int(11) NOT NULL default '0'");
catalog/includes/modules/payment/paypal.php
Line #449 : if ($sniffer->field_exists(TABLE_PAYPAL, 'zen_order_id')) $db->Execute("ALTER TABLE " . TABLE_PAYPAL . " CHANGE COLUMN zen_order_id order_id int(11) NOT NULL default '0'");
Line #626 : $db->Execute("ALTER TABLE " . TABLE_PAYPAL . " CHANGE zen_order_id order_id int(11) NOT NULL default '0'");
**
catalog/includes/modules/payment/paypaldp.php**
Line #1631 : $db->Execute("ALTER TABLE " . TABLE_PAYPAL . " CHANGE zen_order_id order_id int(11) NOT NULL default '0'");
catalog/includes/modules/payment/paypalwpp.php
Line #2952 : $db->Execute("ALTER TABLE " . TABLE_PAYPAL . " CHANGE zen_order_id order_id int(11) NOT NULL default '0'");
catalog/includes/modules/payment/securehosting.php
Line #145 : $sql = "select * from " . TABLE_PAYPAL . " where zen_order_id = '" . $zf_order_id . "' LIMIT 1";
Line #155 : $sql = "INSERT INTO " . TABLE_PAYPAL . " (zen_order_id,txn_id,payment_date,payer_id,reason_code) VALUES ('".$insert_id."','".$_GET['transactionreference']."','".$_GET['transactiondate']." ".$_GET['transactiontime']."','".$_GET['cv2avsresult']."','Success')";
doh.... i hope this means something to you!!
tHANKS!