The combo is a grid editor component so I do not see a way to hook into it, because I do not see one actually being created, just the options for it in the grid.

I am using  12.2.20122.2113.

I have disabled all of the code in the edit cell ended event and it still occurs.  The grid in question has the following features.  Most columns are read only except for a check box and the combo box column.

For now I have made those read only in IE 8.  

var readOnly = (Request.Browser.Browser == "IE") && (Request.Browser.MajorVersion == 8);

settingsBuilder.ColumnSetting().ColumnKey("IsExcludedFlag").ReadOnly(readOnly);
settingsBuilder.ColumnSetting().ColumnKey("Stage").ReadOnly(readOnly).EditorType(ColumnEditorType.Combo)
.ComboEditorOptions(options => {
options.AllowCustomValue(false);
options.Mode(ComboMode.DropDown);
options.ShowDropDownButton(true);
options.DataSource(ViewBag.StatusValues);
options.TextKey("Text");
options.ValueKey("Value");
options.EnableClearButton(false);
options.DropDownOnFocus(true);
options.SelectItemBySpaceKey(true);
});

The grid itself is defined as follows

@(@Html.Infragistics().Grid<PatientGridMember>()
.ID(gridId).PrimaryKey("PatientListMembersID")
.LoadOnDemand(false).AutoGenerateColumns(false).AutoGenerateLayouts(false).EnableUTCDates(true)
.EnableHoverStyles(true).RenderCheckboxes(true).LocalSchemaTransform(true).AutoCommit(true)
.Columns(GenerateChildColumns)
.Features(feature => {
feature.Sorting().Mode(SortingMode.Single);
feature.Selection().Mode(SelectionMode.Row).MultipleSelection(true);
feature.RowSelectors().EnableCheckBoxes(true).EnableRowNumbering(false);
feature.Resizing().AllowDoubleClickToResize(true);
feature.Updating().EditMode(GridEditMode.Cell).
EnableDeleteRow(false).EnableAddRow(false).ColumnSettings(CreateColumnSettings);
})
.DataSource(physician.Members.AsQueryable())
.DataBind()
.CalculateWidthAndHeight()
.Render()
)