It seems using prependTo or appendTo on select elements only move the content of the <select>. The following example demonstrates that. (tested on firefox 2.0.0.2 - linux)

#!xml
         <script type="text/javascript">

             $(document).ready(function() {

                        $('p').appendTo("#foo");
                        $('select').appendTo("#foo");


                     });

         </script>


         <p><span>span</span></p>
         <div id="bar"><select><option>BLEH</option></select></div>
         <div id="foo"></div>

That results in:

#!xml
<div id="bar"><select></select></div>
<div id="foo"><p><span>span</span></p><option>BLEH></option></div>