Hey Linda,
They most definitely do count as duplicate. I build several Joomla websites a month for clients and whilst you can use a rel="canonical" link such as suggested by Todd, I prefer to remove the issue by replacing the standard joomla .htaccess file content with the following content:-
Options +FollowSymLinks
RewriteEngine On
prevents people from accessing anything with phpMyAdmin
RewriteRule phpMyAdmin - [F]
Remove index.php or index.htm/html from URL requests
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /(([^/]+/)*)index.(php|html?)\ HTTP/
RewriteCond %{REQUEST_URI} !^/administrator
RewriteRule ^([^/]+/)*index.(html?|php)$ http://www.domain.com/$1 [R=301,L]
force canonical www if request is for non-www or has port number etc
RewriteCond %{HTTP_HOST} !^(www.example.com)?$
RewriteRule (.*) http://www.domain.com/$1 [R=301,L]
redirect 301 /home.html http://www.domain.com/
RewriteCond %{QUERY_STRING} mosConfig_[a-zA-Z_]{1,21}(=|%3D) [OR]
RewriteCond %{QUERY_STRING} base64_encode[^(]([^)]) [OR]
RewriteCond %{QUERY_STRING} (<|%3C)([^s]s)+cript.(>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} GLOBALS(=|[|%[0-9A-Z]{0,2}) [OR]
RewriteCond %{QUERY_STRING} _REQUEST(=|[|%[0-9A-Z]{0,2})
RewriteRule .* index.php [F]
RewriteBase /
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
RewriteCond %{REQUEST_URI} !^/index.php
RewriteCond %{REQUEST_URI} (/[^.]|.(php|html?|feed|pdf|raw))$ [NC]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . index.php [L]
Before replacing your .htaccess code with the above make sure you take a back-up copy of the original code just in case. Replace www.domain.com with your domain.
Hope this helps.
Ade.
