I have a big problem with this tool because its produce lot of duplicate content in the search results.
Example:
Main Url:

http://www.my-domain.com/

You can also access the main page if you put the letter “?” after the slash.
Example:
I can also see the main page with the following urls:
http://www.my-domain.com/?lamer
http://www.my-domain.com/?this-suxx
http://www.my-domain.com/?whatever-you-want

If your page is accessible under different internal urls, you get an penalty from Google.
How can I fix it?

My htaccess:
RewriteEngine on
RewriteBase /

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.+)$ index\.php/$1 [L,QSA]

Thanks