autocomplete in ASP.NET using ScriptManager broken in Firefox with jQuery 1.9.0

autocomplete in ASP.NET using ScriptManager broken in Firefox with jQuery 1.9.0

I have spent a couple of days on this and narrowed down the issue.  I am using the autocomplete with the new jQuery 1.9.0 and during the select function of the autocomplete I call __doPostBack to send the result back to ASP.NET.  Here is my code: 

  1.     <script type="text/javascript">
  2.          $(document).ready(function () {
  3.             $('.QuickSearch').each(function (index, value) {
  4.                  var QuickSearchURL = $(this).attr('qsURL');
  5.                  var QuickSearchWidth = $(this).attr('qsWidth');
  6.                  $(this).css('width', QuickSearchWidth);
  7.                  $(this).autocomplete({
  8.                      source: function (request, response) {
  9.                          $.ajax({
  10.                              url: QuickSearchURL,
  11.                              data: "{ 'filterby': '" + request.term + "','CONID':'" + getQuerystring('CONID') + "'}",
  12.                              dataType: "json",
  13.                              type: "POST",
  14.                              contentType: "application/json; charset=utf-8",
  15.                              dataFilter: function (data) { return data; },
  16.                              success: function (data) { response($.map(data.d, function (item) { return { label: item.label, value: item.value} })) },
  17.                              error: function (XMLHttpRequest, textStatus, errorThrown) { alert(textStatus); }
  18.                          });
  19.                      },
  20.                      minLength: 1,
  21.                      autoFocus: true,
  22.                      delay: 0,
  23.                      appendTo: 'form',
  24.                      select: function (event, ui) {
  25.                          var submitpostaback = $(this).attr('qsPostBack');
  26.                          var postbacktype = $(this).attr('qsType');
  27.                          var selectedValue = ui.item.value;
  28.                          $(this).val(selectedValue);
  29.                          if (submitpostaback == 'true') {
  30.                              if (ui.item) {
  31.                                  __doPostBack('SEARCHCOMPLETE', selectedValue + '|' + postbacktype);
  32.                              }
  33.                          }
  34.                      }
  35.                  });
  36.              });
  37.          });
  38.          function getQuerystring(key, default_) {
  39.              if (default_ == null) default_ = "";
  40.              key = key.replace(/[\[]/, "\\\[").replace(/[\]]/, "\\\]");
  41.              var regex = new RegExp("[\\?&]" + key + "=([^&#]*)");
  42.              var qs = regex.exec(window.location.href);
  43.              if (qs == null)
  44.                  return default_;
  45.              else
  46.                  return qs[1];
  47.          }
  48.      </script>
How to reproduce the problem:

1) Create an ASP.NET page, add a control for the autocomplete, add the code for it with a postback using __doPostBack.
2) Make sure you add the Scriptmanager control to the page.

Run the application.  When you select an item in the list and click on it, this should postback the result.

This will work in IE and CHROME but will not work in Firefox.   If you remove the scriptmanager it will work in all three.

If you replace the jQuery with version 1.8.7 it will work in all three as well.  So there is some kind of conflict with the new version of jQuery 1.9.0 and the scriptmanager.

Does anyone have any ideas?

Thanks,
Cory