AspNetPager+updatepanel以postback方式回传有关问题，第一页有反应，第二页点了不刷新了

<asp:UpdatePanel ID="UpdatePanel2" runat="server" UpdateMode="Conditional" 
        style="width:566px; float:left;" ClientIDMode="AutoID" 
        ViewStateMode="Enabled">
        <ContentTemplate>
            <asp:Repeater ID="adlistRP" runat="server" ViewStateMode="Enabled" OnItemCommand="adlistRP_ItemCommand" >
               <ItemTemplate>
                 <div class="content">
                   <asp:Image ID="Image1"  ImageUrl='<%#Eval("ss_pic") %>' runat="server" style="margin:5px;width:60px;height:60px;float:left;" />
                   <div style="width:490px;float:right">
                   <div style="margin:5px 0;width:490px;float:right;">
                     <a><%#Eval("ss_name") %>：</a><%#Eval("ad_word") %><%#Eval("ad_id") %></div>
                   <div style="float:right;width:490px;height:25px;">
                       <div style="width:40px;height:25px;float:right; padding-left:3px; border-left:1px solid #dddddd; ">
                       <asp:Button ID="Button2" CommandName="1" CommandArgument='<%#Eval("ad_id")%>' runat="server" Text="评论" style="background-color:white; border: 0px; height:28px; cursor:pointer;" /></div>
                   </div></div>
                   
                   <asp:UpdatePanel runat="server" ID="UPLL" UpdateMode="Conditional" Visible="true" ViewStateMode="Enabled">
                      <ContentTemplate>

                      <div style="float:right; width:490px; background-color:#ECEFF5; margin-top:13px;">
                         <asp:Label ID="LBL" runat="server" Text="waiting" Visible="false" ></asp:Label>
                         <asp:Image ID="Image2" runat="server"  style="float:left; width:40px; height:40px; margin:5px;" />
                         <asp:TextBox ID="comment" runat="server"  TextMode="MultiLine" style="float:left; margin:5px 0; width:420px; height:80px; overflow:hidden;"></asp:TextBox>
                         <asp:Button ID="Do_comment"  CommandName="comment" CommandArgument='<%#Eval("ad_id")%>' runat="server" Text="评论"  
        ForeColor="White" class="button" style="float:right;"/>
                      </div>
                         
                         <asp:Repeater ID="commentlist" runat="server" ViewStateMode="Enabled">
                            <ItemTemplate>
                            <div style="float:right; width:490px; background-color:#ECEFF5; margin-top:2px;">
                              <asp:Image ID="Image3" runat="server" style="float:left; width:40px; height:40px; margin:5px;" />
                              <div style="float:left; width:420px; margin:10px 0;">
                              <div style="float:left; width:420px; font-size:small;"><%#Eval("com_content")%></div>
                              <div style="float:left; width:420px; font-size:small;">用户名 评论时间</div>
                              </div>
                            </div>
                            </ItemTemplate>
                         </asp:Repeater>
                    
                      
                      </ContentTemplate>
                      <Triggers>
                         <asp:AsyncPostBackTrigger ControlID="adlistRP" />
                      </Triggers>                   
                   </asp:UpdatePanel>
                 
                 </div>
               </ItemTemplate>
            </asp:Repeater>
           
        </ContentTemplate>
        <Triggers>
            <asp:AsyncPostBackTrigger ControlID="DropDownList1" />
        </Triggers>
    </asp:UpdatePanel>
    <asp:UpdatePanel ID="pagex" UpdateMode="Conditional" runat="server" 
        style="float:left;clear:left;" ViewStateMode="Enabled">
    <ContentTemplate>
    
    <webdiyer:AspNetPager ID="AspNetPager1" runat="server" Width="610px" FirstPageText="第一页" 
         LastPageText="最后一页" NextPageText="下一页" PrevPageText="上一页" Font-Names="Arial" 
            BackColor="#F8B500" AlwaysShow="true"  
         ShowInputBox="Always" SubmitButtonText="转到" SubmitButtonStyle="botton" 
            OnPageChanging="pageBind_PageChanging" ForeColor="Black" 
         HorizontalAlign="Center" PageSize="10" 
         style="font-size: 12px; color: #0099ff; background-color: #ffffff; text-decoration: none" 
         UrlPaging="false" InvalidPageIndexErrorMessage="请请输入正确的页码!" 
            ShowNavigationToolTip="True" TextAfterInputBox="页" TextBeforeInputBox="第" 
            PageIndexBoxType="DropDownList" PageIndexOutOfRangeErrorMessage="请请输入正确的页码！" 
            ShowPageIndexBox="Always" ViewStateMode="Enabled" >
    </webdiyer:AspNetPager></ContentTemplate>
    <Triggers><asp:AsyncPostBackTrigger ControlID="DropDownList1" /></Triggers>
    </asp:UpdatePanel>