When deployment config contains an invalid option, empty service is deployed with no units

If passing a config file to deploy that contains an invalid configuratoin option for a service, the new service is allocated but no machines are started or associated with the new service. I'd expect juju to either fail, or warn and continue as normal. The new, empty service is capable of being members of relations with other functioning services.

$ juju deploy --repository=. --config=conf.yaml local:keystone
2012-01-10 22:45:58,619 INFO Connecting to environment.
foo is not a valid configuration option.
2012-01-10 22:46:00,709 ERROR foo is not a valid configuration option.

$ juju status
2012-01-10 22:46:04,975 INFO Connecting to environment.
machines:
  0:
    dns-name: ec2-176-34-218-198.eu-west-1.compute.amazonaws.com
    instance-id: i-ea9cfda3
    instance-state: running
    state: running
services:
  keystone:
    charm: local:precise/keystone-101
    relations: {}
    units: {}
2012-01-10 22:46:07,377 INFO 'status' command finished successfully

$ juju add-relation glance:identity-service keystone:identity-service
2012-01-10 22:53:41,870 INFO Connecting to environment.
2012-01-10 22:53:44,187 INFO Added keystone relation to all service units.
2012-01-10 22:53:44,188 INFO 'add_relation' command finished successfully
$ juju status
2012-01-10 22:53:47,494 INFO Connecting to environment.
machines:
  0:
    dns-name: ec2-176-34-218-198.eu-west-1.compute.amazonaws.com
    instance-id: i-ea9cfda3
    instance-state: running
    state: running
  19:
    dns-name: ec2-46-137-151-161.eu-west-1.compute.amazonaws.com
    instance-id: i-485a3a01
    instance-state: running
    state: running
services:
  glance:
    charm: local:precise/glance-47
    relations:
      identity-service: keystone
    units:
      glance/2:
        machine: 19
        public-address: ec2-46-137-151-161.eu-west-1.compute.amazonaws.com
        relations:
          identity-service:
            state: up
        state: started
  keystone:
    charm: local:precise/keystone-101
    relations:
      identity-service: glance
    units: {}
2012-01-10 22:53:51,325 INFO 'status' command finished successfully