ssh password fail

I am trying to connect to a machine using ssh. Have been doing this successfully for more than one year but now the machine rejects my attempts. The password has not changed because I can still use it to vnc into the machine with no problem. ssh diagnostics gave the following results:

PAM: permission denied for username from 82-69-XXX-XXX.dsl.in-addr.zen.co.uk via 128.163.XX.XXX

Failed keyboard-interactive/pam for username from 82.69.47.151 port 57735 ssh2

debug1: userauth-request for user username service ssh-connection method keyboard-interactive [preauth]

debug1: attempt 2 failures 1 [preauth]

debug1: keyboard-interactive devs [preauth]

debug1: auth2_challenge: user=farman devs= [preauth]

debug1: kbdint_alloc: devices 'pam' [preauth]

debug1: auth2_challenge_start: trying authentication method 'pam' [preauth]

Postponed keyboard-interactive for username from 82.69.XXX.XXX port 57735 ssh2 [preauth]

Any ideas?