Rails - Apr 2006 - Making @headers[''Refresh''] and send_file work together?

I''ve got a Rails 1.1 app where people can click a link to download a  
custom-generated file.  The link to "Download Zip" goes to / 
controller/get_zip.  That action looks like this:

   def get_zip
     @cart = find_cart
     ids = Array.new
     @cart.songs.each do |song|
       ids.push song.id
     end

     args = ids.join(" ")
     zipfile = `#{RAILS_ROOT}/perl/buildzip.pl #{args}`
     begin
       size = File.stat(zipfile).size
       @cart.empty!
       filename = "out.zip"
       send_file(zipfile, :filename => filename, :type =>  
"application/zip", :str
eaming => false)
     rescue
       flash[:warning] = "Zip file no longer exists - did you already  
download it
?"
       redirect_to(:controller => "/online")
     end
   end


I''d like to have the user get sent to a different page a few seconds  
after the download starts.  In a previous incarnation of this app,  
I''d set the HTTP "Refresh" header before sending the binary
data.  In
fact, on a standard controller action that just renders RHTML, I can do:

      @headers["Refresh"] = ''5,
url=http://www.cnn.com/''

And it works as expected - 5 seconds after the action is rendered,  
I''m redirected.

However, if I set that header before doing the send_file, nothing  
happens.  The file downloads properly - no problems there - but no  
redirect.  Looking through the source, it doesn''t _seem_ like the  
@headers are getting overwritten, just updated.  But it''s certainly  
not refreshing.

Any thoughts on how to make this work (or another way to accomplish  
what I''m trying to do?