Symfony 1.2 - 返回sfView :: ERROR重定向到SUCCESS

I use Symfony to write my code for about two years, but this is the first time I'm trying to use return sfView::ERROR feature.

The problem is, it doesn't work. Even if my controller looks like:

public function executeSomething(){  

  return sfView::ERROR;

}

and I have two files under templates directory:

somethingSuccess.php
somethingError.php

it still displays success view.

Symfony version is: 1.2

update:

this is part from my debug log:

57  Info PHPView    Render "sf_app_dir/modules/project/templates/somethingSuccess.php"
58  Info PHPView    Decorate content with "sf_app_dir/templates/clean.php"
59  Info PHPView    Render "sf_app_dir/templates/clean.php"
60  Info WebResponse    Send status "HTTP/1.1 200 OK"
61  Info WebResponse    Send header "Content-Type: text/html; charset=utf-8"

even if I add return 'Blabla'; which should get somethingBlabla.php as view, or at least produce error, it still gets SUCCESS.