Bootstrap row-fluid items collapsing

Bootstrap row-fluid items collapsing

I can not understand why the images starting from the second row start
toppling and do not appear as in the first row?

<div class="container-fluid">
<div class="row-fluid">
<div class="span9 offset3">
<?php
$step = 1;
do{
echo <<<EOF
<div class="span4 {$class}" id="p{$rst_catalog['p_id']}">
<a href="pillow.php?p_id={$rst_catalog['p_id']}"><img
src="images/{$rst_catalog['p_img']}" alt="img"
title="{$rst_catalog['p_name']}" /></a>
<div class="row">
<div class="span12">
<a
href="pillow.php?p_id={$rst_catalog['p_id']}">{$rst_catalog['p_name']}</a>
{$rst_catalog['p_rubric']}
{$rst_catalog['p_price1']}.00 ðóá.
</div>
</div>
</div>
EOF;
if ($step == 4)
$step = 11;
else
$step++;
} while ($rst_catalog = mysql_fetch_assoc($res_catalog));
?>
<?php require_once ("inc/inc_show_pagination.php"); ?>
</div>
</div>
</div>
The rest of the code (it is generated through PHP) can be found here