Passwordless ssh, keys not authenticating, asks for password

[Dave]

Hi,
I'm trying to set up passwordless ssh login

I have it working on all but one client, with no obvious reason why it's not 
working on this one box.

Box1 (ubuntu)  uname -a

Linux ubuntu 3.2.0-75-generic #110-Ubuntu SMP Tue Dec 16 19:11:28 UTC 2014 
i686 i686 i386 GNU/Linux


Box2 (testbox - working) uname -a

FreeBSD testbox.asgard.uk 9.3-RELEASE-p9 FreeBSD 9.3-RELEASE-p9 #0: Tue Jan 27 
10:43:40 UTC 2015     root at amd64-
builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC  amd64


Box3 (amd - not working) uname -a

FreeBSD amd.asgard.uk 9.3-RELEASE-p9 FreeBSD 9.3-RELEASE-p9 #0: Tue Jan 27 
10:43:40 UTC 2015     root at amd64-
builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC  amd64


On Box1 I did

ssh-keygen (default answers, no pass phrase)
ssh-copy-id dave at testbox
ssh-copy-id dave at amd
ssh-add


Boxes 2 and 3 have identical and default  /etc/ssh/ssh_config and the following 
are identical.

~/.ssh is chmod 700
-rw-------  1 dave  dave  797  2 Feb 22:10 authorized_keys
-rw-r--r--  1 dave  dave  165  6 Jan 23:27 known_host

ssh dave at testbox (Box2 works fine)
ssh dave at amd     (Box3 fails and asks for the password)


Results of ssh -v dave at amd (Box3)

OpenSSH_5.9p1 Debian-5ubuntu1.4, OpenSSL 1.0.1 14 Mar 2012
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to amd [192.168.1.3] port 22.
debug1: Connection established.
debug1: identity file /home/dave/.ssh/id_rsa type 1
debug1: Checking blacklist file /usr/share/ssh/blacklist.RSA-2048
debug1: Checking blacklist file /etc/ssh/blacklist.RSA-2048
debug1: identity file /home/dave/.ssh/id_rsa-cert type -1
debug1: identity file /home/dave/.ssh/id_dsa type -1
debug1: identity file /home/dave/.ssh/id_dsa-cert type -1
debug1: identity file /home/dave/.ssh/id_ecdsa type -1
debug1: identity file /home/dave/.ssh/id_ecdsa-cert type -1
debug1: Remote protocol version 2.0, remote software version 
OpenSSH_6.6.1_hpn13v11 FreeBSD-20140420
debug1: match: OpenSSH_6.6.1_hpn13v11 FreeBSD-20140420 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.9p1 Debian-5ubuntu1.4
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5 none
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: sending SSH2_MSG_KEX_ECDH_INIT
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ECDSA xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx
debug1: Host 'amd' is known and matches the ECDSA host key.
debug1: Found key in /home/dave/.ssh/known_hosts:1
debug1: ssh_ecdsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,keyboard-interactive
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /home/dave/.ssh/id_rsa
debug1: Authentications that can continue: publickey,keyboard-interactive
debug1: Offering RSA public key: dave at ubuntu
debug1: Authentications that can continue: publickey,keyboard-interactive
debug1: Trying private key: /home/dave/.ssh/id_dsa
debug1: Trying private key: /home/dave/.ssh/id_ecdsa
debug1: Next authentication method: keyboard-interactive
Password for dave at amd.asgard.uk:


Box3 (amd,the problembox)   pkg info | grep ssh

libssh-0.6.3_1                 Library implementing the SSH1 and SSH2 protocol
linux-c6-libssh2-1.4.2_1       Library implementing the SSH2 protocol (Linux 
CentOS 6.6


Box (testbox,a working box) pkg info | grep ssh

libssh-0.6.3_1                 Library implementing the SSH1 and SSH2 protocol

To eliminate the potential difference, pkg info | grep ssh shows no results on 
a 9.2 box where passwordless ssh works.  I also successfully tested with a 
RaspBMC box.

I can only assume there is something different somewhere on Box3 (amd) that 
I've changed and forgotten about.   Is there anything else you need to know to 
help me?