Ok, I think I have found the reason why it is not working on my site.
Actually, the url when I get the "already submitted" message is:
http://mysite.com/searchurl/http://................. (which is
NOT working)
But when I tried:
http://mysite.com/search.php?url=http://................. (It is
WORKING)
So, will someone please tell me how to make set the
searchurl part to
search.php?url= ?
Thank you for the help :)