Cancelling an import from 2nd page of import form produces "selected file could not be copied" + 2 other errors

I have a brand new installation of user_import version 2.3 to ensure nothing else is affecting what I am seeing.

First time in, I select a .csv file to import & progress through to 2nd page of form. At this point, field import_id on table {user_import} = 1. Instead of testing or importing, I click cancel, which redirects me back to the import tab, with a status notification that my import file was deleted, but followed by three error conditions as follows:

• The selected file could not be copied, because no file by that name exists. Please check that you supplied the correct filename.
• warning: fgetcsv() expects parameter 1 to be resource, boolean given in /home/sites/test.casme.com/drupal/sites/all/modules/user_import/user_import.module on line 1361.
• warning: fclose(): supplied argument is not a valid stream resource in /home/sites/test.casme.com/drupal/sites/all/modules/user_import/user_import.module on line 1457.

This would appear to be a problem with $form_state['values']['setting'] = 'file set' still being set after user_import_edit_cancel_validate() completes, which causes the first error on first line of user_import_edit_submit(). I have not had time to investigate further to establish what gives rise to the other two errors for fgetcsv and fclose