Mod Rewrite / 500 internal error

[eluser]Unknown[/eluser]
Hi,

I'm trying to remove the index.php from my url.
Here's my .htacess file.

RewriteEngine on
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ /index.php/$1 [L]

I have change my config.php

$config['index_page'] = "";

And i'm getting an 500 error.

---------------------------------------------

If i change my .htacess rule with a redirection at the end it work fine!

RewriteEngine on
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ /index.php/$1 [R]

But this is not the result i'm looking for....

Any idea why i'm getting this error?