The first is the number of stories under that topic, the second is the number of stories for that topic which are waiting in the submission queue.
You can configure this in config.php:
// Show the number of stories in a topic in Section Block
$_CONF['showstorycount'] = 1;
// Show the number of story submissions for a topic in Section Block
$_CONF['showsubmissioncount'] = 1;
bye, Dirk
