Aiuto htaccess e VBSEO

Ho appena acquistato Vbseo, seguendo le istruzioni di caricare il file htaccess nella directory dell mio forum mi appare una pagina di errore.( io il forum ce l'ho in una sottodirectory chiamata forum, perciò l'url del forum è "www.miosito.altervista.org/forum"

Quando inserisco il file htaccess nella sottodirectory forum mi si sfasa tutto il sito.

Quando inserisco il file htaccess nella root mi da questo errore:

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, info@altervista.org and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.

I codici del file htacess dati da vbseo sono questi:

Codice:

# Comment the following line (add '#' at the beginning) # to disable mod_rewrite functions. # Please note: you still need to disable the hack in # the vBSEO control panel to stop url rewrites. RewriteEngine On # Some servers require the Rewritebase directive to be # enabled (remove '#' at the beginning to activate) # Please note: when enabled, you must include the path # to your root vB folder (i.e. RewriteBase /forums/) #RewriteBase / #RewriteCond %{HTTP_HOST} !^www\.yourdomain\.com #RewriteRule (.*) http://www.yourdomain.com/forums/$1 [L,R=301] RewriteRule ^((urllist|sitemap_).*\.(xml|txt)(\.gz)?)$ vbseo_sitemap/vbseo_getsitemap.php?sitemap=$1 [L] RewriteCond %{REQUEST_URI} !(admincp/|modcp/|cron|vbseo_sitemap|api\.php) RewriteRule ^((archive/)?(.*\.php(/.*)?))$ vbseo.php [L,QSA] RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteCond %{REQUEST_FILENAME} !/(admincp|modcp|clientscript|cpstyles|images)/ RewriteRule ^(.+)$ vbseo.php [L,QSA]

Aiutatemi non so come far apparire il sito normale con vbseo senza che si sfasi

P.s:Nella documentazione sul file htacess dice:

Upload the vBSEO .htaccess file (located in the 'htaccess' folder) to your forum root folder.
Note: In some operating systems, the .htaccess file is not visible. If this is your case, find the htaccess.txt file in the same folder, (1) upload it to your forum root folder and (2) rename it to .htaccess.