using ftp4j to connect through proxy

Question

Is this correct? I could swear it is but its not working and we are trying to track down if its a problem with my code or the proxy setup.

FTPClient client = new FTPClient();
client.setConnector(new SOCKS5Connector(proxy_host, proxy_port));
client.connect(ftp_host, ftp_port);
client.login(ftp_user, ftp_pass);

/*some stuff*/

client.disconnect(true);