This is the output of juju from a clean install with 2 nodes all running 12.04 Precise juju bootstrap - finishes with no errors and allocates the machine to the user but still no joy after juju environment-destroy and rebuild with different users and different nodes.

root@cloudcontrol:/storage# juju -v  status
2012-06-07 11:19:47,602 DEBUG Initializing juju status runtime
2012-06-07 11:19:47,621 INFO Connecting to environment...
2012-06-07 11:19:47,905 DEBUG Connecting to environment using node-386077143930...
2012-06-07 11:19:47,906 DEBUG Spawning SSH process with remote_user="ubuntu" remote_host="node-386077143930" remote_port="2181" local_port="57004".
The authenticity of host 'node-386077143930 (10.5.5.113)' can't be established.
ECDSA key fingerprint is 31:94:89:62:69:83:24:23:5f:02:70:53:93:54:b1:c5.
Are you sure you want to continue connecting (yes/no)? yes
2012-06-07 11:19:52,102 ERROR Invalid SSH key
2012-06-07 11:19:52,426:18541(0x7feb13b58700):ZOO_INFO@log_env@658: Client environment:zookeeper.version=zookeeper C client 3.3.5
2012-06-07 11:19:52,426:18541(0x7feb13b58700):ZOO_INFO@log_env@662: Client environment:host.name=cloudcontrol
2012-06-07 11:19:52,426:18541(0x7feb13b58700):ZOO_INFO@log_env@669: Client environment:os.name=Linux
2012-06-07 11:19:52,426:18541(0x7feb13b58700):ZOO_INFO@log_env@670: Client environment:os.arch=3.2.0-23-generic
2012-06-07 11:19:52,426:18541(0x7feb13b58700):ZOO_INFO@log_env@671: Client environment:os.version=#36-Ubuntu SMP Tue Apr 10 20:39:51 UTC 2012
2012-06-07 11:19:52,428:18541(0x7feb13b58700):ZOO_INFO@log_env@679: Client environment:user.name=sysadmin
2012-06-07 11:19:52,428:18541(0x7feb13b58700):ZOO_INFO@log_env@687: Client environment:user.home=/root
2012-06-07 11:19:52,428:18541(0x7feb13b58700):ZOO_INFO@log_env@699: Client environment:user.dir=/storage
2012-06-07 11:19:52,428:18541(0x7feb13b58700):ZOO_INFO@zookeeper_init@727: Initiating client connection, host=localhost:57004 sessionTimeout=10000 watcher=0x7feb11afc6b0 sessionId=0 sessionPasswd=<null> context=0x2dc7d20 flags=0
2012-06-07 11:19:52,429:18541(0x7feb0e856700):ZOO_ERROR@handle_socket_error_msg@1579: Socket [127.0.0.1:57004] zk retcode=-4, errno=111(Connection refused): server refused to accept the client
2012-06-07 11:19:55,765:18541(0x7feb0e856700):ZOO_ERROR@handle_socket_error_msg@1579: Socket [127.0.0.1:57004] zk retcode=-4, errno=111(Connection refused): server refused to accept the client