Error creating a "View" with a field "Case Tracker: Case Number (Project number?)"

In the "Edit view" form (/admin/build/views/##/edit) -> Fields -> Add field: has a field "Case Tracker: Case number" twice.

Export test species "View" for the first field:

  $view = new stdClass();
  $view->name = 'cs_test';
  $view->description = 'Project number testing';
  $view->access = array (
);
  $view->view_args_php = '';
  $view->page = TRUE;
  $view->page_title = '';
  $view->page_header = '';
  $view->page_header_format = '1';
  $view->page_footer = '';
  $view->page_footer_format = '1';
  $view->page_empty = '';
  $view->page_empty_format = '1';
  $view->page_type = 'list';
  $view->url = 'cs_test';
  $view->use_pager = FALSE;
  $view->nodes_per_page = '20';
  $view->sort = array (
  );
  $view->argument = array (
  );
  $view->field = array (
    array (
      'tablename' => 'casetracker_project',
      'field' => 'project_number',
      'label' => '',
    ),
  );
  $view->filter = array (
  );
  $view->exposed_filter = array (
  );
  $view->requires = array(casetracker_project);
  $views[$view->name] = $view;

Returns empty list!

If I include in the request and second field "Case Tracker: Case number" too, the request is done correctly and returns means both fields.

Sorry for bad English