Operation Name on Node:Delete is "Operation"

Line 115 of userpoints_nc.module, the 'operation' you use for $op = 'delete' in hook_nodeapi is "operation" (it should be 'delete').

Current:

 case 'delete':
      if (variable_get(USERPOINTS_POST . '_undo_points_on_delete', true)) {
        $points = -$points;
        $params = array(
          'points' => $points,
          'uid' => $node->uid,
          'operation' => 'operation',
          'entity_id' => $node->nid,
          'entity_type' => 'node',
        );
        userpoints_userpointsapi($params);
      }
      break;

Should be:
'operation' => t('delete')