IE6 is crap.
Add following code to your site, so people are announced to upgrade IE6:
[code:1]
<!--[if lte IE 6]>
<style type="text/css">
#ie6msg{border:3px solid #090; margin:8px 0; background:#cfc; color:#000;}
#ie6msg h4{margin:8px; padding:0;}
#ie6msg p{margin:8px; padding:0;}
#ie6msg p a.getie7{font-weight:bold; color:#006;}
#ie6msg p a.ie6expl{font-weight:normal; color:#006;}
</style>
<div id="ie6msg">
<h4>TIP: You are using a very old version of Microsoft Internet Explorer.</h4>
<p>
Because of known security issues in that browser and several other problems displaying new web sites you should upgrade to the latest version of Microsoft Internet Explorer or even better to the alternative browser Mozilla Firefox!<br />
The current version of Microsoft Internet Explorer can be downloaded <a class="getie7" href="
www.microsoft.com/germany/windows/internet-explorer/download-ie.aspx
" target="_blank">here and the alternative web browser Mozilla Firefox
<a class="getie7" href="
www.mozilla.com/
" target="_blank">here.
</p>
</div>
<![endif]-->
[/code:1]