I am getting an error when I tried to edit a row from the Webdatagrid:  "Sys_InvalidOperationException Handler was not added through the Sys.UIDomEvent.addHandler method."

               <ig:WebDataGrid ID="grdDateProcess" 
                                   runat="server" 
                                   AutoGenerateColumns="False" 
                                   Width="100%" 
                                   CssClass="GridView"
                                   ItemCssClass="GridViewRow"
                                   OnRowAdded="grdDateProcess_RowAdded"
                                   OnRowAdding="grdDateProcess_RowAdding"
                                   OnRowUpdating="grdDateProcess_RowUpdating"
                                   DataKeyFields="ID"
                                   EnableAjax= "true"
                                   AltItemCssClass="GridViewRowAlternate">
                 <EditorProviders>
                     <ig:DatePickerProvider ID="ApplicationDateProvider" EditorControl-   CssClass="DateChooserTextBox">                                                    
                     </ig:DatePickerProvider>              
                     <ig:DropDownProvider ID="DateTypeProvider">
                     <EditorControl ID="ddlDateType" runat="server" DisplayMode="DropDownList" TextField="DateTypeDesc" 

                                   ValueField="DateTypeID">
                     </EditorControl>
                     </ig:DropDownProvider>
                     </EditorProviders>            
                     <Behaviors>
                           <ig:Sorting Enabled="true" />                                   
                           <ig:ColumnMoving Enabled="true" />
                           <ig:ColumnResizing Enabled="true" />
                           <ig:Paging Enabled="true" PagerAppearance="Top" PageSize="15" PagerMode="NumericFirstLast" 

                                      QuickPages="3" PagerCssClass="PagerCell"/>
                                   <DFI_Behavior:HighlightBehavior/>
                           <ig:Selection Enabled="true" 
                                       SelectionClientEvents-RowSelectionChanged="grdDateProcess_RowSelectionChanged"
                                       RowSelectType="Single" 
                                       CellClickAction="Row" />           

                         <ig:EditingCore>
                               <Behaviors>
                                  <ig:CellEditing Enabled="true">
                                     <EditModeActions EnableF2="true" EnableOnActive="true" MouseClick="Single" />
                                          <ColumnSettings>
                                             <ig:EditingColumnSetting  ColumnKey="ApplicationDate" 

                                                      EditorID="ApplicationDateProvider" />
                                              <ig:EditingColumnSetting  ColumnKey="DateTypeID" EditorID="DateTypeProvider" />
                                            </ColumnSettings>
                                   </ig:CellEditing>

Am I missing something? Thank you.