The following is the code used to set it up. 

I noticed that the class=scroll is not needed with the UI compatibility of version 3.5.3 perhaps this is a clue.

If someone can tell me which function gets fired when the + (for subform expansion) is clicked I might be able to trace around a bit. 

subGrid: true,

subGridRowExpanded: function(subgrid_id, row_id) {

     var subgrid_table_id, pager_id;

     subgrid_table_id = subgrid_id + "_t";

     pager_id = "p_" + subgrid_table_id;

    var DRID = $("#ETSMonth").getCell(row_id, 'DRID');

    var WOID = $('#ETSMonth').getCell(row_id, 'WOID');

    $("#" + subgrid_id).html("<table id='" + subgrid_table_id + "' class='scroll'></table>");

    $("#" + subgrid_table_id).jqGrid({

    mtype: 'POST',

    url: "WSSubGridGetDFSA.aspx", //need a way to pass DRID on initial post

    datatype: "json",

     colModel: [{ label: "Comment", name: "Comment", index: "Comment", width: 1100, editable: true, edittype: "text",      editoptions: { size: 165, maxlength: 250 }, align: 'left' }, ],

     imgpath: "themes/coffee/images",

     postData: { 'UserName': UserName, 'ClientId': ClientId, 'DRID': DRID },

     beforeEditCell: function(rowid, celname, value, iRow, iCol) { return checkApprovedforSubGrid(CurrentRowId); },

     cellEdit: true,

     cellsubmit: 'clientArray',

     cellurl: "WSSubGridSetDFSA.aspx",

     afterSaveCell: function(rowid, celname, value, iRow, iCol) { saveComment(row_id, value, DRID, WOID); }, 

     height: '100%'

    });

},