Using jquery ui accordion on ie6

I want a div to control accordion, div a fixed width and height,

But found ie9 display normal, ie6 is displayed incorrectly

For convenience,I modify the demo (demos\\accordion\\default.html), the code is as follows

use jquery 1.6.2 and jQuery UI 1.8.16

<div class="demo" style="height:150px; overflow:auto;width:800px; border:solid 1px red;">

<div id="accordion" style="width:600px;">

<h3><a href="#">Section 1</a></h3>

<div>1<br />2<br />3<br />4<br />5<br />6<br />7<br />8<br />9<br />10<br />11<br /></div>

<h3><a href="#">Section 2</a></h3>

<div style="height:200px;">2</div>

<h3><a href="#">Section 3</a></h3>

<div style="height:200px;">3</div>

<h3><a href="#">Section 4</a></h3>

<div style="height:200px;">4</div>

</div>

</div>

<script>

$(function() {

$( "#accordion" ).accordion();

});

</script>

ie9 result is as follows,Scroll bar in a div

http://hi.baidu.com/jzzxl2008/album/item/51615583ee8ac5d70df4d26d.html#

ie6 result is as follows,Div scroll bar also, but more than the height of accordion div, and click the accordion, the layout a bit chaotic

http://hi.baidu.com/jzzxl2008/album/item/d37bb539ea6d5ab7d462256d.html#

Hope to get help