Error when terminating ec2 demo

After terminating an ec2 demo instance by hitting Ctrl+D

Postmortem console closed.
terminating Instance:i-241d0743...Traceback (most recent call last):
  File "/home/jml/src/lp-dev-utils/ec2", line 54, in <module>
    main()
  File "/home/jml/src/lp-dev-utils/ec2", line 48, in main
    controller.run(args)
  File "/home/jml/src/lp-dev-utils/ec2test/controller.py", line 148, in run
    run_bzr(argv)
  File "/usr/lib/pymodules/python2.6/bzrlib/commands.py", line 1131, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/pymodules/python2.6/bzrlib/commands.py", line 673, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/pymodules/python2.6/bzrlib/commands.py", line 695, in run
    return self._operation.run_simple(*args, **kwargs)
  File "/usr/lib/pymodules/python2.6/bzrlib/cleanup.py", line 136, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/usr/lib/pymodules/python2.6/bzrlib/cleanup.py", line 166, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/home/jml/src/lp-dev-utils/ec2test/builtins.py", line 542, in run
    demo_network_string)
  File "/home/jml/src/lp-dev-utils/ec2test/instance.py", line 491, in set_up_and_run
    self.shutdown()
  File "/home/jml/src/lp-dev-utils/ec2test/instance.py", line 336, in shutdown
    self._boto_instance.terminate()
AttributeError: 'Instance' object has no attribute 'terminate'

This happened on a machine running 12.04 LTS.