Htaccess.txt to .htaccess

Hi people! Firstly, I want to say that this hosting is something great. Secondaly, I have one problem. I am using joomla 1.5.9. CMS and I have installed sh404 component because I wanted to make my URLs shorter. I read everything in sh404 documents, renamed htacess.txt to . htaccess, turned on mode_rewrite and I added # at the beginning of each line of the first section, and removed those # in front of those in the second section but it still doesnt work. It can open the home page but the rest show me 404 like it doesnt exist. when i back htaccess.txt i works normally.
I noticed that when I use htacces.txt there is index.php (for example: www.mysite.com/download).
I am sorry because my english. If you need more informations, just tell, cause I need to fix this.

Cheers

By the way this is my .htaccess file:

@version $Id: htaccess.txt 10492 2008-07-02 06:38:28Z ircmaxell $

@package Joomla

@copyright Copyright © 2005 - 2008 Open Source Matters. All rights reserved.

@license gnu.org/copyleft/gpl.html GNU/GPL

Joomla! is Free Software

#####################################################

READ THIS COMPLETELY IF YOU CHOOSE TO USE THIS FILE

The line just below this section: ‘Options +FollowSymLinks’ may cause problems

with some server configurations. It is required for use of mod_rewrite, but may already

be set by your server administrator in a way that dissallows changing it in

your .htaccess file. If using it causes your server to error out, comment it out (add # to

beginning of line), reload your site in your browser and test your sef url’s. If they work,

it has been set by your server administrator and you do not need it set here.

#####################################################

Can be commented out if causes errors, see notes above.

Options +FollowSymLinks

mod_rewrite in use

RewriteEngine On

########## Begin - Rewrite rules to block out some common exploits

If you experience problems on your site block out the operations listed below

This attempts to block the most common type of exploit attempts to Joomla!

Block out any script trying to set a mosConfig value through the URL

RewriteCond %{QUERY_STRING} mosConfig_[a-zA-Z_]{1,21}(=|%3D) [OR]

Block out any script trying to base64_encode crap to send via URL

RewriteCond %{QUERY_STRING} base64_encode.(.) [OR]

Block out any script that includes a tag in URL

RewriteCond %{QUERY_STRING} (<|%3C).script.(>|%3E) [NC,OR]

Block out any script trying to set a PHP GLOBALS variable via URL

RewriteCond %{QUERY_STRING} GLOBALS(=|[|%[0-9A-Z]{0,2}) [OR]

Block out any script trying to modify a _REQUEST variable via URL

RewriteCond %{QUERY_STRING} _REQUEST(=|[|%[0-9A-Z]{0,2})

Send all blocked request to homepage with 403 Forbidden error!

RewriteRule ^(.*)$ index.php [F,L]

########## End - Rewrite rules to block out some common exploits

Uncomment following line if your webserver’s URL

is not directly related to physical file paths.

Update Your Joomla! Directory (just / for root)

RewriteBase /

########## Begin - Joomla! core SEF Section
############# Use this section if using ONLY Joomla! core SEF

ALL (RewriteCond) lines in this section are only required if you actually

have directories named ‘content’ or ‘component’ on your server

If you do not have directories with these names, comment them out.

#RewriteCond %{REQUEST_FILENAME} !-f
#RewriteCond %{REQUEST_FILENAME} !-d
#RewriteCond %{REQUEST_URI} ^(/component/option,com) [NC,OR] ##optional - see notes##
#RewriteCond %{REQUEST_URI} (/|.htm|.php|.html|/[^.]*)$ [NC]
#RewriteRule ^(content/|component/) index.php

########## End - Joomla! core SEF Section

########## Begin - 3rd Party SEF Section
############# Use this section if you are using a 3rd party (Non Joomla! core) SEF extension - e.g. OpenSEF, 404_SEF, 404SEFx, SEF Advance, etc

RewriteCond %{REQUEST_URI} ^(/component/option,com) [NC,OR] ##optional - see notes##
RewriteCond %{REQUEST_URI} (/|.htm|.php|.html|/[^.])$ [NC]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule (.
) index.php

########## End - 3rd Party SEF Section

First of all you should use domains which you own for showing examples. (There are specific Domains which are especially for example purposes like “example.com”)
The owner of mysite.com would not be interestet in a lot of 404 error messages in his logfiles.

Then you should comment out the line “Options +FollowSymLinks” with #, this line must cause an error 500.

The rest should work if everything is configured properly.