-> No correct caclulations. I have "earned" more coins than calculated. Not much more, but theres a deviation. (Other user reports correct working calculations) And i really did correct calculations.
You must have messed up, because it works for me. Make sure that you're truncating the result with just four decimal points for the interest. And make sure that you have the deposits and withdrawals marked on the right day (according to BTC Arbs).