JQuery UI sortable 'cancel' option not working in FF

I have a jsFiddle showing the problem. If you open this in FF 32.0.1 (the latest for now) you will notice that <select>

it is not clickable. Chrome works amazingly.

Any suggestions on how to make this work?

Briefly for those who do not want to open the link:

HTML:

<ul id="sortable">
    <li><span>drag me 1
        <select>
            <option value="somevalue1">some value 1</option>
            <option value="somevalue2">some value 2</option>
        </select>
        </span>
    </li>
    <li><span>drag me 2</span></li>
    <li><span>drag me 3</span></li>
    <li><span>drag me 4</span></li>
</ul>

      

        
        
        
      

    

js (using cancel docs):

$("#sortable").sortable({
    handle: "span",
    cancel: "select"
}).disableSelection();

      

        
        
        
      

    

CSS

span {
    cursor: move;
}
#sortable {
    list-style-type: none;
}
#sortable li {
    margin: 3px;
    height: 30px;
    background-color: gray;
}