500 Internal server error when clicking links

Code:

<IfModule mod_rewrite.c>

    RewriteEngine On

    RewriteBase /



    #Removes access to the system folder by users.

    #Additionally this will allow you to create a System.php controller,

    #previously this would not have been possible.

    #'system' can be replaced if you have renamed your system folder.

    RewriteCond %{REQUEST_URI} ^system.*

    RewriteRule ^(.*)$ /index.php?/$1 [L]

    

    #When your application folder isn't in the system folder

    #This snippet prevents user access to the application folder

    #Submitted by: Fabdrol

    #Rename 'application' to your applications folder name.

    RewriteCond %{REQUEST_URI} ^application.*

    RewriteRule ^(.*)$ /index.php?/$1 [L]



    #Checks to see if the user is attempting to access a valid file,

    #such as an image or css document, if this isn't true it sends the

    #request to index.php

    RewriteCond %{REQUEST_FILENAME} !-f

    RewriteCond %{REQUEST_FILENAME} !-d

    RewriteRule ^(.*)$ index.php?/$1 [L]

    

</IfModule>



<IfModule !mod_rewrite.c>

    # If we don't have mod_rewrite installed, all 404's

    # can be sent to index.php, and everything works as normal.

    # Submitted by: ElliotHaughin



    ErrorDocument 404 /index.php

</IfModule>

Code:

// by Phil Sturgeon

// Let's hold Windows' hand and set a include_path in case it forgot

set_include_path(dirname(__FILE__));



// Some hosts (was it GoDaddy? complained without this

@ini_set('cgi.fix_pathinfo', 0);



// PHP 5.3 will BITCH without this

if(ini_get('date.timezone') == '')

{

    date_default_timezone_set('GMT');

}