jQuery(this).footerData('set',{ae:aeTotal});     //details footer
    jQuery('#grid').footerData('set',{ae:newEpaAe}); //master footer
    jQuery('#grid').setCell(rowId, 'ae', aeTotal);   //master row
    //master group summary??

jQuery("#grid").jqGrid('destroyGroupHeader');

jQuery("#grid").jqGrid('setGroupHeaders', {
  useColSpanStyle: true,
  groupHeaders:[
    {startColumnName: 'amount', numberOfColumns: 3, titleText: '<em>Price</em>'},
    {startColumnName: 'closed', numberOfColumns: 2, titleText: 'Shiping'}
  ]
});
...