Implode errors, bad queries using OR operator

Perhaps I misunderstand the thinking behind the operator, but when using the "OR" operator, I get the following errors with my view:

    * warning: implode() [function.implode]: Bad arguments. in /sites/all/modules/views_fastsearch/views_fastsearch.module on line 140.
    * user warning: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '))' at line 1 query: SELECT count(node.nid) FROM node node LEFT JOIN users_roles users_roles ON node.uid = users_roles.uid INNER JOIN users users ON node.uid = users.uid LEFT JOIN content_type_bio node_data_field_first_name ON node.vid = node_data_field_first_name.vid LEFT JOIN content_type_bio node_data_field_last_name ON node.vid = node_data_field_last_name.vid WHERE (users_roles.rid = '3') AND (node.type IN ('bio')) AND (()) in /includes/database.mysql.inc on line 172.
    * user warning: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')) ORDER BY node_data_field_last_name_field_last_name_value ASC LIMIT 0, 50' at line 1 query: SELECT node.nid, users.uid AS users_uid, node_data_field_first_name.field_first_name_value AS node_data_field_first_name_field_first_name_value, node_data_field_last_name.field_last_name_value AS node_data_field_last_name_field_last_name_value FROM node node LEFT JOIN users_roles users_roles ON node.uid = users_roles.uid INNER JOIN users users ON node.uid = users.uid LEFT JOIN content_type_bio node_data_field_first_name ON node.vid = node_data_field_first_name.vid LEFT JOIN content_type_bio node_data_field_last_name ON node.vid = node_data_field_last_name.vid WHERE (users_roles.rid = '3') AND (node.type IN ('bio')) AND (()) ORDER BY node_data_field_last_name_field_last_name_value ASC LIMIT 0, 50 in /includes/database.mysql.inc on line 172.

Currently I'm working around this, but I'd like to be able to do an OR based keyword search.

Here's the view export, for yr reference:

  $view = new stdClass();
  $view->name = 'directory';
  $view->description = 'Staff Directory';
  $view->access = array (
);
  $view->view_args_php = '';
  $view->page = TRUE;
  $view->page_title = 'IFTF Staff Directory';
  $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 = 'table';
  $view->url = 'people/directory';
  $view->use_pager = TRUE;
  $view->nodes_per_page = '50';
  $view->menu = TRUE;
  $view->menu_title = 'directory';
  $view->menu_tab = FALSE;
  $view->menu_tab_weight = '0';
  $view->menu_tab_default = FALSE;
  $view->menu_tab_default_parent = NULL;
  $view->menu_tab_default_parent_type = 'tab';
  $view->menu_parent_tab_weight = '0';
  $view->menu_parent_title = '';
  $view->sort = array (
  );
  $view->argument = array (
  );
  $view->field = array (
    array (
      'tablename' => 'users',
      'field' => 'uid',
      'label' => '',
    ),
    array (
      'tablename' => 'node_data_field_first_name',
      'field' => 'field_first_name_value',
      'label' => 'First Name',
      'handler' => 'content_views_field_handler_group',
      'sortable' => '1',
      'options' => 'default',
    ),
    array (
      'tablename' => 'node_data_field_last_name',
      'field' => 'field_last_name_value',
      'label' => 'Last Name',
      'handler' => 'content_views_field_handler_group',
      'sortable' => '1',
      'defaultsort' => 'ASC',
      'options' => 'default',
    ),
  );
  $view->filter = array (
    array (
      'tablename' => 'users_roles',
      'field' => 'rid',
      'operator' => 'AND',
      'options' => '',
      'value' => array (
  0 => '3',
),
    ),
    array (
      'tablename' => 'node',
      'field' => 'type',
      'operator' => 'OR',
      'options' => '',
      'value' => array (
  0 => 'bio',
),
    ),
    array (
      'tablename' => 'search_index',
      'field' => 'word',
      'operator' => 'AND+',
      'options' => '',
      'value' => '',
    ),
  );
  $view->exposed_filter = array (
    array (
      'tablename' => 'search_index',
      'field' => 'word',
      'label' => '',
      'optional' => '1',
      'is_default' => '0',
      'operator' => '1',
      'single' => '0',
    ),
  );
  $view->requires = array(users, node_data_field_first_name, node_data_field_last_name, users_roles, node, search_index);
  $views[$view->name] = $view;