February missing

Odd one this. Click the calendar view - shows Jan. Click Next - shows just the head (see attached image). Click next - shows all of March. Where did February go?

View export:

  $view = new stdClass();
  $view->name = 'calendar';
  $view->description = 'Calendar view of any date field';
  $view->access = array (
);
  $view->view_args_php = '';
  $view->page = TRUE;
  $view->page_title = 'Calendar';
  $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 = 'calendar';
  $view->url = 'calendar';
  $view->use_pager = FALSE;
  $view->nodes_per_page = '99';
  $view->menu = TRUE;
  $view->menu_title = 'Calendar';
  $view->menu_tab = FALSE;
  $view->menu_tab_default = FALSE;
  $view->menu_tab_weight = '0';
  $view->block = TRUE;
  $view->block_title = '';
  $view->block_header = '';
  $view->block_header_format = '1';
  $view->block_footer = '';
  $view->block_footer_format = '1';
  $view->block_empty = '';
  $view->block_empty_format = '1';
  $view->block_type = 'calendar';
  $view->nodes_per_block = '99';
  $view->block_more = TRUE;
  $view->block_use_page_header = FALSE;
  $view->block_use_page_footer = FALSE;
  $view->block_use_page_empty = FALSE;
  $view->sort = array (
    array (
      'tablename' => 'node',
      'field' => 'changed',
      'sortorder' => 'ASC',
      'options' => 'normal',
    ),
  );
  $view->argument = array (
    array (
      'type' => 'calendar_year',
      'argdefault' => '2',
      'title' => 'Year',
      'options' => '',
      'wildcard' => '',
      'wildcard_substitution' => '',
    ),
    array (
      'type' => 'calendar_month',
      'argdefault' => '2',
      'title' => 'Month',
      'options' => '',
      'wildcard' => '',
      'wildcard_substitution' => '',
    ),
    array (
      'type' => 'calendar_day',
      'argdefault' => '2',
      'title' => 'Day',
      'options' => '',
      'wildcard' => '',
      'wildcard_substitution' => '',
    ),
  );
  $view->field = array (
    array (
      'tablename' => 'node',
      'field' => 'type',
      'label' => 'Type:',
    ),
    array (
      'tablename' => 'node',
      'field' => 'title',
      'label' => 'Title:',
      'handler' => 'views_handler_field_nodelink',
      'options' => 'link',
    ),
    array (
      'tablename' => 'node_data_field_date',
      'field' => 'field_date_value',
      'label' => '',
      'handler' => 'content_views_field_handler_group',
      'options' => 'default',
    ),
  );
  $view->filter = array (
    array (
      'tablename' => 'node',
      'field' => 'status',
      'operator' => '=',
      'options' => '',
      'value' => '1',
    ),
    array (
      'tablename' => 'node',
      'field' => 'type',
      'operator' => 'OR',
      'options' => '',
      'value' => array (
  0 => 'birthday',
),
    ),
    array (
      'tablename' => 'node_data_field_age',
      'field' => 'field_age_value_default',
      'operator' => '>',
      'options' => '',
      'value' => '',
    ),
  );
  $view->exposed_filter = array (
  );
  $view->requires = array(node, node_data_field_date, node_data_field_age);
  $views[$view->name] = $view;