Zip file not downloading properly in IE

hi,
Here is my code.

<% require ‘rubygems’
require ‘zip/zipfilesystem’
content = “”
content += “[InternetShortcut]\n”
content += “URL=http://www.mysite.com/”
content += “\nIconFile=http://www.mysite.com/favicon.ico\n”
File.delete("#{RAILS_ROOT}/public/ins_test/InsShortcut.zip") if
File.exist?("#{RAILS_ROOT}/public/ins_test/InsShortcut.zip")
Zip::ZipFile.open("#{RAILS_ROOT}/public/ins_test/InsShortcut.zip",
Zip::ZipFile::CREATE){
|zipfile|
zipfile.file.open(“MySite.url”, ‘w’) { |f| f.puts “#{content}” }
}
File.chmod(0777, “#{RAILS_ROOT}/public/ins_test/InsShortcut.zip”)

  %>
  <a href="/ins_test/InsShortcut.zip">download the shortcut icon

(zipped)

local - OS(ubuntu 8.04) When I download the zipped file in both IE &
firefox it is working properly.

Server - OS(red hat 5.2) In firefox zipped file is downloading properly
but not in IE.

I am not able to understand the situation, is it because of OS or my
code.

Advance Thanks.
Raju