Javascript jquery draggable div

What could cause the draggable option to not be set for an element.

I have these jquery settings.

	<link rel="stylesheet" href="http://jqueryui.com/themes/base/jquery.ui.all.css">
	<script src="http://jqueryui.com/jquery-1.5.1.js"></script>
	<script src="http://jqueryui.com/ui/jquery.ui.core.js"></script>
	<script src="http://jqueryui.com/ui/jquery.ui.widget.js"></script>
	<script src="http://jqueryui.com/ui/jquery.ui.mouse.js"></script>
	<script src="http://jqueryui.com/ui/jquery.ui.resizable.js"></script>
             <script src="http://jqueryui.com/ui/jquery.ui.draggable.js"></script>

and try to turn off the draggable option in code like this.

             editable.parent().draggable({disable: true});
             editable.parent().draggable("option", "disable", true);

editable.parent() does find the right element, but the draggable option isn’t turned off.