Download File WOrks in Firefox not in IE7

Hi,

I have a popup page that suppose to open to let the user download the file that is stored in session variable. This page works fine in FireFox and it dows not work in IE7. In FireFox the open file dialog show up and you can download the file. in IE7 the popup page opens and closes but no open file dialog. Does any body have any ideas on what is wrong? Here is the code for the whole page.

 using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.IO;

public partial class ShowFile : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
      
     &nbs ...