The last edition of Code Igniter need work to use rewrite module?

[eluser]Unknown[/eluser]
Hello.

I checked up the recent version code-igniter and updated.
But the short-url, which is applied rewrite-module, is not working.

In previous version 2.1.0, it is working well. I don't know the reason.

My rewrite-rule is this:
<IfModule mod_rewrite.so>
RewriteEngine On
RewriteBase /clean/
RewriteCond %{REQUEST_URI} ^codeigniter.*
RewriteRule ^(.*)$ /index.php?/$1 [L]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ /index.php?/$1 [L]
</IfModule>
<IfModule !mod_rewrite.c>
ErrorDocument 404 /index.php
</IfModule>

test: http://localhost/clean/{$controller Name}
It don't work..

And my server's rewrite engine is on status.

Please tell me the matter and what I should to solve it.
(But... I'm not good at English, please say easily even children can understand