Problem with query

[HellCore]

Hi,
I have a part of query which works on localhost but not on my VPS server

SELECT * FROM ps_order_discount
LEFT JOIN ps_orders ON ps_order_discount.id_order = ps_orders.id_order AND name = '$user

' 
LEFT JOIN ps_order_detail ON ps_order_detail.id_order = ps_orders.id_order 
LEFT JOIN ps_order_history ON ps_order_history.id_order = ps_orders.id_order
WHERE DATE_SUB(CURDATE(),INTERVAL 18 DAY) <= ps_order_history.date_add and (module='cashondelivery' OR module='transferuj' AND id_order_state = 2 OR module='paypal' AND id_order_state = 2)

Everything is fine except this:
DATE_SUB(CURDATE(),INTERVAL 18 DAY) <= ps_order_history.date_add

This part should shows records that are 18 days old from today but it doesn't work. 
Maybe something is wrong on phpMyAdmin or plesk settings?