You probably already know this, but perhaps to state the obvious... Bitcoin value changes very quickly, even in the space of hours. In the past month alone, we've seen swings of almost 50%, so it's very likely you bought your coins at a price about 10% higher than it is right now. Post your wallet address if you want/can, someone here should be able to pinpoint what happened.
You sent bitcoin. It would be more interesting talking using bitcoin values, not euros.
Also, giving your transaction id would be helpful.
![Smiley](https://bitcointalk.org/Smileys/default/smiley.gif)
Yup. Am pretty sure the balance would tally, if kept strictly in units of Bitcoin.