title: telerik grid with gridclientselectcolumn and hierarchy select doesn't mark selected marks on postback
body: <p>I have telerik grid with hierarchy and  gridclientselectcolumn on the external table on my aspx page.</p>
  
  <pre><code>  &lt;telerik:RadAjaxPanel runat="server"&gt;
                  &lt;telerik:RadGrid ID="rgUsersInSessions" ShowStatusBar="true" OnNeedDataSource="OnNeedDataSourceForGrid" OnDetailTableDataBind="OnDetailTableDateBind" OnItemDataBound="OnAnswerItemBound" runat="server" AutoGenerateColumns="False" PageSize="10"
                      AllowSorting="True" AllowMultiRowSelection="False" AllowPaging="True" GridLines="None"&gt;
                      &lt;ClientSettings AllowExpandCollapse="True"&gt;
                          &lt;Selecting AllowRowSelect="True"&gt;&lt;/Selecting&gt;
                          &lt;ClientEvents OnHierarchyExpanding="RowExpanded" /&gt;
                      &lt;/ClientSettings&gt;
                      &lt;PagerStyle Mode="NumericPages"&gt;&lt;/PagerStyle&gt;
                      &lt;MasterTableView EnableHierarchyExpandAll="true" AllowMultiColumnSorting="True" ClientIDMode="Static" HierarchyLoadMode="Conditional"&gt;
                          &lt;DetailTables&gt;
                              &lt;telerik:GridTableView HierarchyLoadMode="Conditional" EnableHierarchyExpandAll="true" Width="100%" runat="server" ClientIDMode="Static" ShowHeader="False"&gt;
                                      &lt;Columns&gt;
                                      &lt;telerik:GridTemplateColumn UniqueName="userQuestion"&gt;
                                          &lt;ItemTemplate&gt;
                                              &lt;asp:Label  Text='&lt;%# DataBinder.Eval(Container.DataItem, "EventId").ToString() %&gt;'&gt;&lt;/asp:Label&gt;                                     
                                          &lt;/ItemTemplate&gt;
                                      &lt;/telerik:GridTemplateColumn&gt;
                                  &lt;/Columns&gt;
                              &lt;/telerik:GridTableView&gt;
                              &lt;/DetailTables&gt;
                          &lt;Columns&gt;  
                               &lt;telerik:GridBoundColumn UniqueName="SessionUserId" Display="False" AllowFiltering="false" DataField="SessionUserId" DataType="System.Int32"&gt;
                              &lt;/telerik:GridBoundColumn&gt;
                           &lt;/Columns&gt;
                      &lt;/MasterTableView&gt;
                  &lt;/telerik:RadGrid&gt;
              &lt;/telerik:RadAjaxPanel&gt;
  </code></pre>
  
  <p>Also I have a LinkButton</p>
  
  <pre><code>&lt;asp:Button runat="server" OnClick="OnApproveButtonClick"/&gt;
  </code></pre>
  
  <p>In the event handler I try to get selected items count  as </p>
  
  <pre><code>rgUsersInSessions.SelectedItems.Count
  </code></pre>
  
  <p>But I get 0 when I checked several items at UI page.</p>
  
  <p>When I try to check the select all checkbox (in the header of grid), I get js error</p>
  
  <blockquote>
    <p>Uncaught TypeError: Cannot call method 'get_element' of null
    Telerik.Web.UI.RadGrid._selectAllRows
    onclick</p>
  </blockquote>
  
  <p>Any ideas, how to get the selected items at server side using gridclientselectcolumn ?</p>