Send_file method on windows and webrick

I am developing in a windows xp environment running WEBrick and MySQL,
RoR 0.13.1. I am trying to retrieve the file that I uploaded via Rails
using the send_file() method. Instead of returning the file, the file’s
contents are being printed out to the WEBrick console, the browser hangs
for a while, and then an empty file is returned from the download dialog
box (Firefox 1.0.7/IE 6.02). Here is the code I am using to return the
file -

class AttachmentController…

def download
attachment = Attachment.find(params[:id])
send_file(attachment.path) #path is
c:/project_dir/upload/user/file_to_send.txt
end

Any ideas or experience with this? I have searched high and low for
related problems but I have come up empty. Any help would be much
appreciated.

Paul