Gridview Displays duplicate Data

[Ramesh B]

I have a web page which has a Update Panel within that I have an Panel (which has a User Control with Gridview control)
I am having an issue while browsing the application, if the data in the column to display is more than 2000 characters approximately the data in the gridrow is duplicating, but its not happening if the characters are less than 2000 characters.
Appreciate your inputs.
Here is the main panel html

<form id="forminitialImpact" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server" />
<asp:UpdatePanel ID="UpdatePanelImitialImpact" runat="server" EnableViewState="True" UpdateMode="Conditional">
<ContentTemplate>
<asp:Panel ID="pnlContentArea" runat="server" Height="610px" HorizontalAlign="Left"
 ScrollBars="Auto" Width="100%"> 
<div id="mainDiv">
<table>
<tr>
  <td colspan="2" class="contentarea">
<ucComment:Comments ID="ucComments" runat="server" EnableViewState="true" />
  </td>
</tr></table>
</asp:Panel>
</ContentTemplate>
</asp:UpdatePanel>
</form>
 

Here is the html of User Control:

<%@ Control Language="C#" AutoEventWireup="true" CodeFile="Comments.ascx.cs" Inherits="Forms_Controls_Comments" %>
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="ajaxToolkit" %>
<link href="../StyleSheet/StyleSheet.css" rel="stylesheet" type="text/css" />
<asp:Panel ID="Comment_HeaderPanel" runat="server" Style="cursor: pointer;">
    <asp:ImageButton ID="Comment_ToggleImage" runat="server" ImageUrl="~/Images/collapse.jpg"
        CausesValidation="false" AlternateText="Collapse" />
    <span class="sectionHeader">Comments</span>
    <ajaxToolkit:CollapsiblePanelExtender ID="cpComments" runat="server" TargetControlID="Comment_ContentPanel"
        Collapsed="False" ExpandControlID="Comment_HeaderPanel" ImageControlID="Comment_ToggleImage"
        CollapseControlID="Comment_HeaderPanel" ExpandDirection="Vertical" SuppressPostBack="true">
    </ajaxToolkit:CollapsiblePanelExtender>
</asp:Panel>
<asp:Panel ID="Comment_ContentPanel" runat="server" Width="100%">
    <table id="tblComments" width="100%">
        <tr>
            <td class="leftAlign">
                <asp:Label ID="lblMiComment" runat="server"></asp:Label></td>
        </tr>
        <tr>
            <td class="leftAlign">
                <asp:GridView Width="100%" AutoGenerateColumns="False" ID="gvComments" runat="server" AllowPaging="True" OnPageIndexChanging="gvComments_PageIndexChanging" PageSize="3">
                    <Columns>
                        <asp:BoundField HeaderText="Comment" DataField="Comment">
                            <HeaderStyle Font-Underline="True" VerticalAlign="Bottom" Wrap="True" />
                            <ItemStyle HorizontalAlign="Left" Wrap="True" />
                        </asp:BoundField>
                    </Columns>
                    <HeaderStyle Wrap="True" />
                    <AlternatingRowStyle BackColor="#E0E0E0" />
                </asp:GridView>
            </td>
        </tr>
        <tr>
            <td class="leftAlign">
                <asp:Label ID="lblNewComent"  Text="Add Comment:" runat="server"></asp:Label><br />
                <asp:TextBox ID="txtCommentEdit" runat="server" TextMode="MultiLine" Width="50%"
                    CssClass="textboxLeftAlign" Height="40px"></asp:TextBox></td>
        </tr>
    </table>
</asp:Panel>