He Fillip,
u was right !
The responsable is this piece of code in the footer.
It's a "scroll to top" code.
---
<style type='text/css'>
#bttop{border:1px solid #000000;background:#696969;text-align:center;padding:5px;position:fixed;bottom:20p x;right:20px;cursor

ointer;display:none;color:#ff f;font-size:11px;font-weight:900;}
#bttop:hover{border:1px solid #ffa789;background:#ff6734;}
</style>
<div id='bttop'>TOP</div>
<script src='http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js' type='text/javascript'></script>
<script type='text/javascript'>$(function(){$(window).scroll(function (){if($(this).scrollTop()!=0){$('#bttop').fadeIn() ;}else{$('#bttop').fadeOut();}});$('#bttop').click (function(){$('body,html').animate({scrollTop:0},8 00);});});</script>
---