NameError: global name 'last_mailed' is not defined

Using Ubuntu 12.04, python 2.7.3

Traceback (most recent call last):
  File "/root/bzr-email-notifier-1.5/bzr_email_notifier.py", line 371, in <module>
    main()
  File "/root/bzr-email-notifier-1.5/bzr_email_notifier.py", line 105, in main
    send_commit_emails_for_branch(branch, relative_path, last_emailed_revisions)
  File "/root/bzr-email-notifier-1.5/bzr_email_notifier.py", line 211, in send_commit_emails_for_branch
    for revid in revisions_to_send(branch, last_emailed_revision):
  File "/root/bzr-email-notifier-1.5/bzr_email_notifier.py", line 251, in revisions_to_send
    last_mailed, self.path, self._option_name))
NameError: global name 'last_mailed' is not defined