JQuery_Countdown : Nothing happen onExpiry callback "finished".

Seems quiz_question_answering_form has changed, now there are two buttons #edit-submit and #edit-navigation-submit-hidden.
Therefore the condition (buttons.length == 1) always evaluates False.
Even the time is out user stay on the same question form page.
In quiz_take_question function :

function finished() {
              // Find all buttons with a name of 'op'.
              var buttons = jQuery('input[type=submit][name=op], button[type=submit][name=op]');
              // Filter out the ones that don't have the right op value.
              buttons = buttons.filter(function() {
                return this.value == $button_op1 || this.value == $button_op2;
              });
              if (buttons.length == 1) {
                // Since only one button was found, this must be it.
                buttons.click();
              }
              else {
                // Zero, or more than one buttons were found; fall back on a page refresh.
                window.location = window.location.href;
              }
            }