title: ValidationSummary doesn't show Errors
body: <p>I have a problem with my gridview which won't show the ValidationSummary-errors anymore. The Headertext of the ValidationSummary does show up as well as the * which I set to appear whenever the ExpressionValidation fires.</p>
  
  <p>I'm quite sure it worked before, but I don't know why it doesn't anymore. At first I thought it might have something to do with the other GridViews on the page as I have like 5 different GridView in different TabPanels, but I already made one validationgroup per GridView.</p>
  
  <p>Markup:</p>
  
  <pre><code>&lt;asp:UpdatePanel runat="server" UpdateMode="Always"&gt;
      &lt;ContentTemplate&gt;
         &lt;asp:GridView ID="gvBBG" runat="server" AutoGenerateColumns="false" DataKeyNames="ID" SkinID="gvWithoutWidth"&gt;
           &lt;Columns&gt;
              &lt;asp:TemplateField&gt;
                  &lt;ItemTemplate&gt;
                     &lt;asp:ImageButton runat="server" ImageUrl="~/Images/GridView/gv_edit.png" CommandName="Edit"/&gt;
                  &lt;/ItemTemplate&gt;
                  &lt;EditItemTemplate&gt;
                     &lt;asp:ImageButton runat="server" ImageUrl="~/Images/GridView/gv_cancel.png" CommandName="Cancel" CausesValidation="false"/&gt;
                     &lt;asp:ImageButton Id="ibUpdate" runat="server" ImageUrl="~/Images/GridView/gv_update.png" CommandName="Update"  CausesValidation="true"
                          ValidationGroup="UpdateBBG" Enabled="true" OnClientClick="return confirm('Datensatz einspielen/aktualisieren?')"/&gt;
                  &lt;/EditItemTemplate&gt;
             &lt;/asp:TemplateField&gt;
             &lt;asp:TemplateField HeaderText="KV West" HeaderStyle-HorizontalAlign="Left"&gt;
                 &lt;EditItemTemplate&gt;
                      &lt;asp:TextBox ID="tbKVWest" runat="server" Text='&lt;%# Bind("KVWestFormatted") %&gt;' ValidationGroup="UpdateBBG" Width="50px" Height="15px"&gt;&lt;/asp:TextBox&gt;
                       &lt;asp:RequiredFieldValidator ID="rfvKVWest" ValidationGroup="UpdateBBG" runat="server"
                             ControlToValidate="tbKVWest" ErrorMessage="Bitte KVWest als Summe angeben"
                             SetFocusOnError="true"&gt;*&lt;/asp:RequiredFieldValidator&gt; 
                        &lt;asp:RegularExpressionValidator ID="revKVWest" ValidationGroup="UpdateBBG" runat="server"
                             ValidationExpression="^[0-9]{1,9}((\,)[0-9]{1,2})?$" ControlToValidate="tbKVWest" SetFocusOnError="true"&gt;*&lt;/asp:RegularExpressionValidator&gt;
                &lt;/EditItemTemplate&gt;
                &lt;ItemTemplate&gt;
                    &lt;%# Eval("KVWestFormatted")%&gt;
                &lt;/ItemTemplate&gt;
          &lt;/asp:TemplateField&gt;
  ....
        &lt;/Columns&gt;
            &lt;EmptyDataTemplate&gt;Keine Daten vorhanden&lt;/EmptyDataTemplate&gt;
    &lt;/asp:GridView&gt;
        &lt;p&gt;
              &lt;asp:ValidationSummary ID="vsUpdate3" runat="server" ShowMessageBox="true" ShowSummary="true" ValidationGroup="UpdateBBG" Font-Bold="true" ForeColor="Red" 
                   EnableClientScript="true" Enabled="true" HeaderText="Validierung..." /&gt;
        &lt;/p&gt;
  </code></pre>
  
  <p></p>
  
  <p>Would be nice if you guys could help me out here. Im not quite sure what the problem is .. maybe it's the UpdatePanel? Maybe I made some dumb mistake ..? I'm rather clueless.</p>