yes, I know this issue, but this is how it works. the mode count the size of the whole torrent, not only of selected pieces. this is because it didn't changed very much since the 2.1 version, when you wasn't be albe to select witch part do you want to download. maybe I'll change it, but not soon I'm affraid. Now I have many things to do.
but on the pictures you shared I see another problem: the torrent is 6GB but quota counts only 2GB? I'll check it.