My first, and default, favourite connections is an SFTP connection. Between the option of this connection (command E) I have "User name: anonymous". When I try to use my connection, I find the user name pre-set to anonymous, I replace it with "root" and I write my password. At first the connection never work (and the pass is corrct, you can trust me). When I try again it always works fine. If I change the connection option, writing "root" in the "User name" field, it always works fine at its first trial.