Whenever I enter a url which isn't the default, I get redirected to dir above root

[eluser]gunnarflax[/eluser]
[quote author="toopay" date="1302647181"]open your .htaccess file, and replace it ALL with this...

Code:

RewriteEngine On
RewriteBase /admin/

RewriteCond %{REQUEST_URI} ^system.*
RewriteRule ^(.*)$ /index.php?/$1 [L]

RewriteCond %{REQUEST_URI} ^application.*
RewriteRule ^(.*)$ /index.php?/$1 [L]

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

[/quote]

With this code I get an Internal Server Error (500)