<IfModule rewrite_module>
RewriteEngine on
RewriteCond %{REQUEST_URI} !^/(skin|js)/
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-l
#RewriteRule ^(.+)$ /default.php/$1 [L]
RewriteRule .* default.php [L]
</IfModule>
thanks a lot