You should use `-p 1934' to specify the port:
usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]
[-D [bind_address:]port] [-e escape_char] [-F configfile]
[-i identity_file] [-L [bind_address:]port:host:hostport]
[-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]
[-R [bind_address:]port:host:hostport] [-S ctl_path]
[-w local_tun[:remote_tun]] [user@]hostname [command]
Unless your version of ssh is different. (I don't know if debian's port uses different options)
Other things to check is the permissions of your home directory, the .ssh directory and your private key.
Try "ssh -vv -p 1934 username@host" to provide more debug feedback on the particular reason for the denial.
The permissions will be checked if the server uses the StrictMode option. If the server can't resolve your hostname, then the UseDNS option can cause a login failure.