Sitewide Tags changes permalink only of custom post type

Hello.

I’m running a WordPress Multisite subdomain based upgraded from MU.
I usually use Sitewide Tags to pull posts to the main blog (http:/mainblog.com) with no problems.
In a new subdomain (http:/blog4.example.com) I decided to use a custom post type with 7 custom taxonomies, one of them hierarchical.
My custom post types appears in the blog4 like this:
http:/blog4.example.com/see/CPT-title.
I want that these custom post type appear (as regular posts from the other subblogs) in the mainblog.
As this type of post does’nt exist in the mainblog, I created it in this mainblog with the same properties that the one in blog4.
Doesn’t work.
I supposed that something in the plugin Sitewide Tags should be added to take my CPT.
I searched on google and found some other people with the same problem but no answers.
Boone Gorges proposes a function that adds this custom post type here:

function add_product_type( $allowed_post_types ) {
$allowed_post_types['product'] = true;
return $allowed_post_types;
}
add_filter( ‘sitewide_tags_allowed_post_types’, ‘add_product_type’ );
?>

It almost worked. Now, if I create a regular post in blog4, it is pulled to the mainblog, with the permalink:
http://blog4.example.com/regular-post-title
But when I create a “product” type in blog4 is pulled as well, but with the permalink changed to:
http:example.com.index.php/cpt-title

I’m not an expert in php, (nor in english, sorry but getting better in both), and I don’t know why this happens.

Don’t know if it is because of it’s a mu upgraded, mainblog or subblog permalink configuration, rewrite slug in the creation of the custom post type, htaccess misconfiguration, even I’ve read about a php imposibility because a problem with cache and “switch to blog”..

I’m lost, so any help is very appreciated. Thanks in advance..