Mobile Safari screwing up your position: fixed content when you blur out of a form field? This will solve it.

gistfile1.js

fix_mobile_scrolling = function() {
  var current_body_scroll_top = $('body').scrollTop();
  window.setTimeout(function (s) {
    $('body').scrollTop(s + 1);
    window.setTimeout(function (s) {
      $('body').scrollTop(s);
    }, 10, s)
  }, 10, current_body_scroll_top);
};