Leo,

We're seeing something that would take seconds to complete to minutes to complete.  The record size was range of 200-400 rows.  We see the issue on IE 10 and IE 11.

The common layout settings we're using are the following:

<LayoutSettings AllowAddNew="No" AllowBatchUpdate="true" AllowColumnSizing="Yes"
                        AllowColumnMove="Yes" AllowColumnFreezing="No" AutoHeight="true" AllowEdit="Yes"
                        AllowExport="Yes" AllowDelete="No" AllowFilter="Yes" AllowGrouping="No" AllowMultipleSelection="Yes"
                        AllowSelectColumns="Yes" AllowSorting="Yes" ApplyFiltersKey="Enter" CellClickAction="RowSelect"
                        EditOnClick="True" GridLineColor="#727272" GridLines="Both" GridLineStyle="Solid"
                        PagingMode="ClassicPaging" PagingSize="500" PagingStyleUI="Slider" GroupByBoxVisible="false"
                        HeaderClickAction="SortMulti" HelpURL="tools.aspx" VerboseEditingInformation="false"
                        NewRowLostFocusAction="AlwaysUpdate" FocusNewRowOnLastCell="true" PagingExportMode="ExportAllData"
                        InProgressUIBehavior="ChangeCursorToHourGlass" HeaderWrapDefault="true" ColumnFooterAggregateMode="CalculateAllData"
                        PagingDetectPartialGroupRows="True" ColumnFooters="Yes" ShowFilterStatus="True"
                        ShowColumnAction="true" Hierarchical="false" HierarchicalMode="LoadOnDemand"
                        RowHeightDefault="-1px" AutoWidth="true">