求教一个关于自定义控件的属性在VS2005的设计器中有时候报错的问题

namespace Toiletry.UI
{
    /// <summary>
    /// 繼承Repeater控件，添加分頁功能
    /// </summary>
    [ToolboxData("<{0}:DataRepeater runat='server' RecordCount=\"100\"><HeaderTemplate><table><tr><td>Header1</td><td>Header2</td></tr></HeaderTemplate><ItemTemplate><tr><td>Data1</td><td>Data2</td></tr></ItemTemplate><FooterTemplate></table></FooterTemplate> </{0}:DataRepeater>")]
    public class DataRepeater : System.Web.UI.WebControls.Repeater
    {
        [Category("分頁")]
        [DefaultValue(0)]
        public int RecordCount
        {
            get
            {
                object o = ViewState["RecordCount"];

                return o == null ? 0 : Convert.ToInt32(o);
            }
            set
            {
                ViewState["RecordCount"] = value;
            }
        }

        [Category("分頁")]
        [DefaultValue(0)]
        public virtual int PageIndex
        {
            get
            {
                object o = ViewState["PageIndex"];

                return o == null ? 0 : Convert.ToInt32(o);
            }
            set
            {
                ViewState["PageIndex"] = value;
            }
        }

        [Category("分頁")]
        [DefaultValue(10)]
        public virtual int PageSize
        {
            get
            {
                object o = ViewState["PageSize"];

                return o == null ? 10 : Convert.ToInt32(o);
            }
            set
            {
                ViewState["PageSize"] = value;
            }
        }

        [Category("分頁")]
        [DefaultValue(true)]
        public bool EnablePaging
        {
            get
            {
                object o = ViewState["EnablePaging"];

                return o == null ? true : Convert.ToBoolean(o);
            }
            set
            {
                ViewState["EnablePaging"] = value;
            }
        }

        public override void RenderControl(HtmlTextWriter writer)
        {
            Table PageTable = new Table();
            PageTable.RenderBeginTag(writer);

            #region "Data Row"

            TableRow DataRow = new TableRow();
            DataRow.RenderBeginTag(writer);

            //Data Cell
            TableCell DataCell = new TableCell();
            DataCell.RenderBeginTag(writer);

            //Repeater控件的內容
            base.RenderControl(writer);

            DataCell.RenderEndTag(writer);

            DataRow.RenderEndTag(writer);

            #endregion

            //允許分頁時，才呈現分頁控件
            if (EnablePaging == true)
            {
                #region "Page Row"

                TableRow PageRow = new TableRow();
                PageRow.RenderBeginTag(writer);

                //Page Cell
                PageCell PCell = new PageCell(RecordCount, PageIndex, PageSize);
                PageRow.Cells.Add(PCell);

                PageRow.RenderControl(writer);

                PageRow.RenderEndTag(writer);

                #endregion
            }

            PageTable.RenderEndTag(writer);     
        }
    }

    public class PageCell : System.Web.UI.WebControls.TableCell
    {
        /// <summary>
        /// 總記錄數
        /// </summary>
        private int _RecordCount;

        /// <summary>
        /// 當前頁碼[索引從0開始，即0=第1頁]
        /// </summary>
        private int _PageIndex;

        /// <summary>
        /// 每頁顯示的記錄筆數
        /// </summary>
        private int _PageSize;

        /// <summary>
        /// 總共有多少頁
        /// </summary>
        private int _PageCount;

        /// <summary>
        /// 在分頁控件上，顯示多少個[頁碼鏈接]
        /// </summary>
        private int _PageLinkCount = 8;

        /// <summary>
        /// 構造函數
        /// </summary>
        /// <param name="RecordCount">總記錄數</param>
        /// <param name="PageIndex">當前頁碼[索引從0開始，即0=第1頁]</param>
        /// <param name="PageSize">每頁顯示的記錄筆數</param>
        public PageCell(int RecordCount, int PageIndex, int PageSize)
        {
            _RecordCount = RecordCount;
            _PageIndex = PageIndex;
            _PageSize = PageSize;

            //_PageSize=0的異常
            if (_PageSize == 0)
            {
                _PageSize = 10;
            }

            //求一共有幾頁
            if (_RecordCount % _PageSize == 0)
            {
                _PageCount = _RecordCount / _PageSize;
            }
            else
            {
                _PageCount = _RecordCount / _PageSize + 1;
            }

            //產生分頁控件
            InitPageControl();
        }

        /// <summary>
        /// 產生分頁控件
        /// </summary>
        public virtual void InitPageControl()
        {
            //當前是第幾頁
            int CurrentPageIndex = _PageIndex + 1;

            //頁碼排列的中間值
            int MiddleValue = 0;

            //頁碼排列中間左邊有幾個
            int LeftCount = 0;

            //頁碼排列中間右邊有幾個
            int RightCount = 0;

            if (_PageLinkCount % 2 == 0)
            {
                MiddleValue = _PageLinkCount / 2 + 1;
                LeftCount = _PageLinkCount / 2;
                RightCount = _PageLinkCount / 2 - 1;
            }
            else
            {
                MiddleValue = (_PageLinkCount - 1) / 2 + 1;
                LeftCount = (_PageLinkCount - 1) / 2;
                RightCount = (_PageLinkCount - 1) / 2;
            }

            //當前頁碼<=中間值
            if (CurrentPageIndex <= MiddleValue)
            {
                if (_PageCount >= _PageLinkCount)
                {
                    for (int i = 1; i <= _PageLinkCount; i++)
                    {
                        LinkButton PageLink = new LinkButton();
                        PageLink.Text = i.ToString();

                        //分隔符
                        Literal PageBlank = new Literal();
                        PageBlank.Text = "&nbsp";

                        //add to control
                        this.Controls.Add(PageLink);
                        this.Controls.Add(PageBlank);
                    }
                }
                else
                {
                    for (int i = 1; i <= _PageCount; i++)
                    {
                        LinkButton PageLink = new LinkButton();
                        PageLink.Text = i.ToString();

                        //分隔符
                        Literal PageBlank = new Literal();
                        PageBlank.Text = "&nbsp";

                        //add to control
                        this.Controls.Add(PageLink);
                        this.Controls.Add(PageBlank);
                    }
                }
            }
            else
            {
                //當前頁碼>中間值

                //處理原則，是把當前頁作為頁碼排列的中間值處理

                //左部分
                for (int i = 1; i <= LeftCount;i++)
                {
                    LinkButton PageLink = new LinkButton();
                    PageLink.Text = (CurrentPageIndex - MiddleValue + 1).ToString();

                    //分隔符
                    Literal PageBlank = new Literal();
                    PageBlank.Text = "&nbsp";

                    //add to control
                    this.Controls.Add(PageLink);
                    this.Controls.Add(PageBlank);
                }

                //中間值
                LinkButton MidPageLink = new LinkButton();
                MidPageLink.Text = CurrentPageIndex.ToString();

                //分隔符
                Literal MidPageBlank = new Literal();
                MidPageBlank.Text = "&nbsp";

                //add to control
                this.Controls.Add(MidPageLink);
                this.Controls.Add(MidPageBlank);

                //右部分
                if (_PageCount - CurrentPageIndex >= RightCount)
                {
                    for (int i = 1; i <= RightCount; i++)
                    {
                        LinkButton PageLink = new LinkButton();
                        PageLink.Text = (CurrentPageIndex + i).ToString();

                        //分隔符
                        Literal PageBlank = new Literal();
                        PageBlank.Text = "&nbsp";

                        //add to control
                        this.Controls.Add(PageLink);
                        this.Controls.Add(PageBlank);
                    }
                }
                else
                {
                    for (int i = 1; i <= _PageCount - CurrentPageIndex; i++)
                    {
                        LinkButton PageLink = new LinkButton();
                        PageLink.Text = (CurrentPageIndex + i).ToString();

                        //分隔符
                        Literal PageBlank = new Literal();
                        PageBlank.Text = "&nbsp";

                        //add to control
                        this.Controls.Add(PageLink);
                        this.Controls.Add(PageBlank);
                    }
                }               
            }
        }

    }

}

WEB頁面的
aspx代碼：

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="DataRepeaterDemo.aspx.cs" Inherits="DataRepeaterDemo" %>

<%@ Register Assembly="Toiletry.UI" Namespace="Toiletry.UI" TagPrefix="cc1" %>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>未命名頁面</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>

        <cc1:DataRepeater ID="rpList" runat="server" RecordCount="1001" EnablePaging="true">
       
           <HeaderTemplate>
            <table class="tby">
            <tr>
                 <th>Age</th>
                 <th>Name</th>
              </tr>
            </HeaderTemplate>
            <ItemTemplate>
            <tr>
             <td><%#Eval("Age")%></td>
             <td><%#Eval("Name")%></td>
             </tr>
            </ItemTemplate>
            <FooterTemplate>
            </table>
            </FooterTemplate>           
       
        </cc1:DataRepeater>
        <cc1:DataRepeater ID="DataRepeater1" runat="server" RecordCount="100">
                   <HeaderTemplate>
            <table class="tby">
            <tr>
                 <th>Age</th>
                 <th>Name</th>
              </tr>
            </HeaderTemplate>
            <ItemTemplate>
            <tr>
             <td><%#Eval("Age")%></td>
             <td><%#Eval("Name")%></td>
             </tr>
            </ItemTemplate>
            <FooterTemplate>
            </table>
            </FooterTemplate> 
        </cc1:DataRepeater>
        <cc1:DataRepeater ID="DataRepeater2" runat="server" RecordCount="100" EnablePaging="false">
            <HeaderTemplate>
                <table>
                </table>
                    <tr>
                        <td>
                            Header1</td>
                        <td>
                            Header2</td>
                    </tr>
            </HeaderTemplate>
            <ItemTemplate>
                <tr>
                    <td>
                        Item1</td>
                    <td>
                        Item2</td>
                </tr>
            </ItemTemplate>
            <FooterTemplate>
                </table></FooterTemplate>
        </cc1:DataRepeater>
   
    </div>
    </form>
</body>
</html>