Sory if I write something wrong, I'm from Portugal, and I dont have much experience writing in English.
So here it is
After a few days looking arround all the information about the function Import, I finaly found the SIMPLE Solution to the problem.
on - wp-admin/wp-settings.php - arround line 302 we have:
if (!strstr($_SERVER['PHP_SELF'], 'install.php') && !strstr($_SERVER['PHP_SELF'], 'wp-admin/import')) :
// Used to guarantee unique hash cookies
$cookiehash = ''; // Remove in 1.4
define('COOKIEHASH', '');
endif;
So the only thing to do is remove this code on the 1st line:
&& !strstr($_SERVER['PHP_SELF'], 'wp-admin/import')
So it will look like this:
if (!strstr($_SERVER['PHP_SELF'], 'install.php')):
// Used to guarantee unique hash cookies
$cookiehash = ''; // Remove in 1.4
define('COOKIEHASH', '');
endif;
For me is working very well.