Paypal payment error warning: Amount $ Paid Instead of $

[meimeisi]

i have issue where customer paid the correct amount but the paypal and prestashop sent payment error email to me and my customer

 

"Warning: S$ 94.27 paid instead of S$ 94.50 !"

 

i do not know what's wrong with the module or the settings.

 

I am using PS 1.3.6 and paypal module 1.6

 

hope to hear solution from you =)