ActionMailer Inline Image Attachment Issue

I have been wholely unsuccessful in having an inline image attachment
show in an HTML email. I have been able to create an email with plain,
html and image parts, but when attempting to set the content-id for an
image (so that I can refer back to it in the HTML), I am unable to get
it to appear using the headers attribute of the attachment.

Here is my code:
class Mailer < ActionMailer::Base

def email_html( user, to, subject, message )
@recipients = “[email protected]
@from = user.emailaddr
@subject = subject

part :content_type => "text/html",
  :body => "<b>Welcome to <img src=\"cid:img1\" border=1>!</b>"

part "text/plain" do |p|
  p.body = "this is plain"
  p.transfer_encoding = "base64"

attachment :content_type => "image/gif",
    :headers => {'content-id' => 'img1'},
    :body =>"c:\temp\logo.gif"),
    :filename => "logo"

    # this works[].filename = 'foo'

    # this does not work[].headers['content-id'] = 'bar'



Please help!