Yo, Alex,
When I was using GB I noticed the same thing. I believe / think, that a "hit in" will only count in the stats if it comes from another domain / subdomain in your cluster's trade database. A hit from elsewhere, a bookmark, etc., does not get counted in GB's stats.
Anyhell, make sure this:
Code:
<?php echo "<img src=\"http://www.domain.com/gb/gbin.php?referer=$HTTP_REFERER\" border=\"0\" width=\"0\" height=\"0\">";?>
is in your head tags in your pages.