i dont think you want to be checking if the recordset is empty, i think you want to be checking if the column for the menu item is empty:
<?php if ($row_rsContent['Manualurl'] != "") { ?>
<li><span><a href="http://www.bamr.co.za/<?php echo $row_rsContent['Manualurl']; ?>" target="_blank"><?php echo $row_rsContent['TabManual']; ?></a></span></li>
<?php } ?>