Hi, i am coadmining this site with Dr_Michael. I have modified the querys needed to not display threads from the hidden boards. Here are the modified querys in case someone is interested, the changes are in bold :
$boards_result = mysql_query("SELECT * FROM {$db_prefix}boards
WHERE ID_BOARD!=21 AND ID_BOARD!=23 ORDER BY numPosts DESC LIMIT 10");
$topic_reply_result = mysql_query("SELECT {$db_prefix}topics.*,m.* FROM {$db_prefix}topics,{$db_prefix}messages as m, {$db_prefix}messages as mes WHERE (m.ID_MSG={$db_prefix}topics.ID_FIRST_MSG &&
mes.ID_MSG={$db_prefix}topics.ID_LAST_MSG
&& ID_BOARD!=21 && ID_BOARD!=23) ORDER BY {$db_prefix}topics.numReplies DESC LIMIT 10");
$topic_view_result = mysql_query("SELECT {$db_prefix}topics.*,m.* FROM {$db_prefix}topics,{$db_prefix}messages as m, {$db_prefix}messages as mes WHERE (m.ID_MSG={$db_prefix}topics.ID_FIRST_MSG &&
mes.ID_MSG={$db_prefix}topics.ID_LAST_MSG
&& ID_BOARD!=21 && ID_BOARD!=23) ORDER BY {$db_prefix}topics.numViews DESC LIMIT 10");
Of course you should change the numbers 21 and 23 with the ids of your hidden boards. You can also add more "&& ID_BOARD!=X", if you have more than 2 hidden boards.