There is a problem with sortables made of unordered lists (at lest in IE7). Suppose you have

<ul class="sortable" id="sortable">

<li class="sortableitem">Item 1</li>

<li class="sortableitem">Item 2</li>

</ul>

<style type="text/css">

.sortable{

margin:0;

padding-left:0px;

list-style: none;

}

.sortableitem

{

cursor:default;

border:1px solid silver;

background:#f0f0ee;

margin:1px;

padding-left:2px;

}

</style>

<script type="text/javascript">

$(document).ready(

function () {

$('ul').Sortable(

{

accept : 'sortableitem',

axis: 'vertically',

}

)

}

);

</script>

The problem is as follows: when you start dragging an element it changes it's width/left offset. It is quite strange because in firefox everything is ok. It is certainly not a browser bug because everything is fine in script.aculo.us sortable demo.