Anton, there is a problem while in the way D7 is configured, PayPal only accept $. As soon as you switch to € you get the PayPal warning that vendor doesn't accept other then $ payment. Do you have a solution for this for somebody based in the heart of Europe, where prices/payments in $ are an unacceptable?
As I know you need to change the default currency in your PayPal to EURO and in Dolphin admin panel -> Modules -> Payment -> Settings block too. When both of them is set to the same currency PayPal should accept payments.