Table view sort problems

Situation: a table view with many fields, most of which have sorting enabled and one is listed as the default sorting field. When one accesses the page view, everything seems fine, as the nodes are sorted according to the default sorting field. However, if one tries to sort according to any other field, the desired sorting doesn't happen and the default-sorted view is returned. Running: Views HEAD, Drupal head, Apache/2.0.59, PHP/5.1.6 and MySQL 5.0.19. Here's the view:

  $view = new stdClass();
  $view->name = 'workspace';
  $view->description = 'Personal user workspace.';
  $view->access = array (
  0 => '3',
  1 => '2',
);
  $view->view_args_php = '';
  $view->page = TRUE;
  $view->page_title = 'My workspace';
  $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 = 'workspace';
  $view->use_pager = FALSE;
  $view->nodes_per_page = '50';
  $view->menu = TRUE;
  $view->menu_title = '';
  $view->menu_tab = FALSE;
  $view->menu_tab_default = FALSE;
  $view->menu_tab_weight = '0';
  $view->sort = array (
    array (
      'tablename' => 'node',
      'field' => 'created',
      'sortorder' => 'DESC',
      'options' => 'normal',
    ),
  );
  $view->argument = array (
  );
  $view->field = array (
    array (
      'tablename' => 'node',
      'field' => 'type',
      'label' => 'Type',
      'sortable' => '1',
    ),
    array (
      'tablename' => 'node',
      'field' => 'title',
      'label' => 'Title',
      'handler' => 'views_handler_field_nodelink',
      'sortable' => '1',
      'options' => 'link',
    ),
    array (
      'tablename' => 'node',
      'field' => 'created',
      'label' => 'Created',
      'handler' => 'views_handler_field_date_small',
      'sortable' => '1',
      'defaultsort' => 'DESC',
    ),
    array (
      'tablename' => 'node',
      'field' => 'changed',
      'label' => 'Modified',
      'handler' => 'views_handler_field_date_small',
      'sortable' => '1',
    ),
    array (
      'tablename' => 'node_comment_statistics',
      'field' => 'comment_count',
      'label' => 'Comments',
      'handler' => 'views_handler_comments_with_new',
      'sortable' => '1',
    ),
    array (
      'tablename' => 'node',
      'field' => 'edit',
      'label' => '',
    ),
    array (
      'tablename' => 'node',
      'field' => 'delete',
      'label' => '',
    ),
  );
  $view->filter = array (
    array (
      'tablename' => 'node',
      'field' => 'currentuid',
      'operator' => '=',
      'options' => '',
      'value' => '***CURRENT_USER***',
    ),
    array (
      'tablename' => 'node',
      'field' => 'distinct',
      'operator' => '=',
      'options' => '',
      'value' => array (
  0 => 'distinct',
),
    ),
  );
  $view->exposed_filter = array (
  );
  $view->requires = array(node, node_comment_statistics);
  $views[$view->name] = $view;