CodeIgniter rewriting URL with FastCGI (PHP-FPM) returned 404

I got this issues some days ago, when my CI based apps returned 404 error when i accessing it. My machine is running Slackware with httpd + PHP-FPM. This issue is not appear when i used httpd/apache + mod_php.

This issue is like httpd's rewrite module is not enabled. But, i have made sure that that module had been activated. After searching and googling, I found solution from here.

From that article, we should be doing something tricky.

And this is my new .htaccess (edited from CI's .htaccess)

Options -Indexes
# index file can be index.php, home.php, default.php etc.
DirectoryIndex index.php

# Rewrite engine
RewriteEngine On

# condition with escaping special chars
RewriteCond $1 !^(index\.php|robots\.txt|favicon\.ico)
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
# the following is for rewritting under FastCGI
<IfModule mod_php5.c>   
    RewriteRule ^(.*)$ index.php/$1 [L,QSA]
</IfModule>

# the following is for rewritting under FastCGI
<IfModule !mod_php5.c>   
    RewriteRule ^(.*)$ index.php?/$1 [L,QSA]
</IfModule>

From that code, the added script is apache define which module is activated, if use mod_php5, do rule --> RewriteRule ^(.*)$ index.php/$1 [L,QSA],
But if not used mod_php5 (using FastCGI), do rule -->RewriteRule ^(.*)$ index.php?/$1 [L,QSA].

The difference is just the "?" after index.php

Okay, thats all.

NB: I used -> CodeIgniter ver 3.0, HTTPD ver 2.4.23 and PHP-FPM ver 5.6.22