htaccess problem urgent - site down

[eluser]Unknown[/eluser]
Codeigniter htaccess started problem all of a sudden today. Even when no changes were made to any files.

Here is my present htaccess

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]
  
#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
#This last condition enables access to the images and css folders, and the robots.txt file
#Submitted by Michael Radlmaier (mradlmaier)
RewriteCond $1 !^(index\.php|images|robots\.txt|css)
RewriteRule ^(.*)$ 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>

I can access www.mysite.com/index.php/controller/method

but it gives a 404 when I access www.mysite.com/controller/method

it is not even a codeigniter 404. It is a general 404.

Any help is appreciated. Since the site is down. Thanks in advance.