Need vouchers that do not effect shipping costs

[Skazz]

Hi, I hope you guys can help me, I'm really close to getting my prestashop up and running, but I need some advice on editing some code.

 

I'm using prestashop 1.4.5.1 and when discount voucher codes are applied to a cart prior to checkout, it not only applies the discount to the order value but if the voucher exceeds the product total, it applies to shipping;

 

for example, if someone has a voucher for £30 and a product for £20 and a shipping cost of £10, instead of reissuing a new voucher for £10 (the remainder from the original voucher without shipping costs), it will apply the remaining £10 to the shipping cost. I want for vouchers to not count towards shipping costs.

 

I look forward to hearing from you all soon, I just have no idea what to do!

 

Thanks again