Hi,
I used Google to translate your message, so apologies if I didn't get it right.
The statement, i.e. the list of settled bets, in Test Mode is stored on your computer, that is why you can delete it by pressing the button next to the "Statement" link. But the real statement is downloaded from BetFair, so you cannot delete it, that's why the button is greyed out when you switch to real mode.
As for the other problem, you may want to experiment with the Account Statement settings (in Portuguese, "Extrato da conta" in "Opções Gerais"). If you set "Requisitar dados que não sejam mais antigos que" to the value of 0, your settled bets will be picked for today only, and all previous bets will be ignored.