discount on cart that i dont give.!

Hi, i have some days here, i am new, and sometime i dont understand somethings., for example, all my discount are on cero like say de box on pricing

"Put '0' in this field if you want to turn off all discounts on your site. ",

so, why if all the discount are cero....i confirm them 2 time, when custumer go to cart, just to pay, the price is another more shipper

pic attachment.

plis let me know, thanks
SOLVED.........the explorer was saving a cuopons in the cache, that i test. so every time that i was testing a product, it was reading the discount coupon.!!!!uffff