Yes, this can happen. Better, it can be explained:
This slight difference arises from the currency conversion. The conversion rate on our website is refreshed on a daily basis and based on the euro value. We know, from experience, that not all banks and credit card companies use the same currency conversion rates and they may process the payment on a different day which can cause small discrepancies. This is in addition to the foreign transaction charge. Your bank can provide you with the details about this.
Please note: We cannot adjust any invoice or paperwork based on the different currency conversion your bank or credit card company charges.