在页面中导出excel，保存文件时出现javascript错误“拒绝访问”?

有一个DataGrid列表的页面，上面有Checkbox等(声明：这个页面在框架中),在win2000、win2003（没打sp1补丁）下，在导出到excel时，弹出保存文件的窗口后，点保存就会出现javascript错误，提示是“拒绝访问”。并且页面上的checkbox也不能选了，点击就出错，直接打开或取消没问题。这什么解决？
在winXP SP2下和win2003 SP1下都没有问题。不知道和系统有没有关系，或者哪位能告诉我win2000升级什么补丁不报错了也可以。
谢谢。

以下是导出代码大家帮忙看看：


private void ExportQuestions(DataSet ds)
{
object missing=Missing.Value;

Excel.Application excel = null;

Excel.Workbooks workbooks = null;

Excel.Workbook workbook = null;

Excel.Sheets sheets = null;

Excel.Worksheet worksheet = null;

excel = new Excel.ApplicationClass();

try
{

string excelname="";

excelname=this.tikunameTextbox.Text + "123.xls";

string filename=System.Web.HttpContext.Current.Server.MapPath("../")+"\\excel\\"+excelname;

FileInfo sTemplate = new FileInfo(System.Web.HttpContext.Current.Server.MapPath("../")+"\\templet\\123.xls"); //导入Excel模板

sTemplate.CopyTo(filename,true); //拷贝生成Excel新文件

///////////////参数初始化//////////////////
int sum=0;


excel.Visible = false;

excel.DisplayAlerts = false;

workbooks = excel.Workbooks;

workbook = workbooks.Open(filename,missing,missing,missing,missing,missing,missing,missing,missing,missing,missing,missing,missing,missing,missing);

sheets = workbook.Worksheets;

worksheet = (Excel.Worksheet)sheets[1];

// worksheet.Name = "试题导出列表"; //设置表名

// oCells = worksheet.Cells;

sum=1;

for(int i=0;i<ds.Tables[0].Rows.Count;i++) //写入Excel
{
worksheet.Cells[sum,1]=ds.Tables[0].Rows[i]["aa"].ToString().Trim();
worksheet.Cells[sum,2]=ds.Tables[0].Rows[i]["bb"].ToString().Trim();

sum++;
}

excel.get_Range(excel.Cells[1,1],excel.Cells[sum-1,2]).Borders.LineStyle = 1;

ds.Dispose();

workbook.Save();

System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook);

workbook = null;

workbooks.Close();

System.Runtime.InteropServices.Marshal.ReleaseComObject(workbooks);

workbooks = null;

System.Runtime.InteropServices.Marshal.ReleaseComObject(excel);

excel = null;

GC.Collect();

System.Web.HttpContext.Current.Response.Clear();

System.Web.HttpContext.Current.Response.ClearHeaders();

System.Web.HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(excelname));

System.Web.HttpContext.Current.Response.ContentType = "application/octet-stream";

FileStream myFile = File.OpenRead(filename); //读取文件进入FileStream

byte[] fileCont = new byte[myFile.Length];

myFile.Read(fileCont,0,(int)myFile.Length); //将文件流中的内容转成byte数组

System.Web.HttpContext.Current.Response.BinaryWrite(fileCont);

System.Web.HttpContext.Current.Response.Flush();

System.Web.HttpContext.Current.Response.Clear();

System.Web.HttpContext.Current.Response.Close(); //关闭文件流

myFile.Close();

}
catch
{
if(workbook!=null)
{
System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook);
}

workbook = null;
if(workbooks!=null)
{

workbooks.Close();

System.Runtime.InteropServices.Marshal.ReleaseComObject(workbooks);

workbooks = null;
}

if(excel!=null)
{
System.Runtime.InteropServices.Marshal.ReleaseComObject(excel);

}
excel = null;

GC.Collect();

System.Web.HttpContext.Current.Response.Clear();

System.Web.HttpContext.Current.Response.ClearHeaders();
Page.RegisterStartupScript("mess","<script>alert('导出失败！');</script>");
}
}