validation problem

[eluser]mdowns[/eluser]
Try checking the row only if num_rows > 0:

Code:

$query = $this->user_model->getUser($str);
if($query->num_rows()>0){
  $row = $query->row();

  if(strtolower($str) == strtolower($row->username)){
    $this->validation->set_message('checkUsername', 'The %s "'. $str . '" is already taken.');
    return FALSE;
  }
}

return TRUE;