first thanks for your prompt answer,
but i can not solve easily the issue,
i've tried to change to add the foolowing lines to my .htaccess:
RewriteEngine On
rewritecond %{http_host} ^sudiunverso.it
rewriteRule ^(.*) http://www.sudiunverso.it/$1 [R=301,L]
but i still have the popup with the website in and i can't logout.
and i've also tried to change the canvas url without success. in attach you have the actual setting of my fb app.
so now i have tried to disable ARTIO joomsef and now it works!!!
Could you suggest me what options to set on ARTIO joomsef? or what kind of question forward to the ARTIO joomsef developers?
Many thx
Andrea