IE bug with HTTP_ACCEPT HTTP header, and workaround

Internet Explorer only sends an "HTTP_ACCEPT" header once per HTTP session.

To see the bug, load this page once in IE and below you'll see the HTTP_ACCEPT header which your browser sent to the server.  Reload and it becomes just "*/*".  Fortunately, you can work around this by capturing that info elsewhere the first time it's sent.

Bug Demo:

Workaround Demo:

My Workaround Code (ASP):

'IE HTTP_Accept workaround: Cookie should last the duration of the browser's HTTP session.
IF Request.Cookies.Item("HTTP_ACCEPT") = ""  THEN
	Response.Cookies.Item("HTTP_ACCEPT") = Request.ServerVariables("HTTP_ACCEPT")
END IF

Notes:

• Why is this bug bad?  My bug discovery experience was this: I needed to write code to decide whether to return data as an Excel spreadsheet or as a CSV text file.  I've heard of similar needs with smartly sending content-types for XHTML (a different IE bug).
• Info: An HTTP session differs from the Session in ASP/.Net & other server-side platforms.  Importantly here is that (I think) it lasts as long as the browser is open (same place Integrated Authentication credentials are cached, I'd guess).
• AFAIK, this only affects Internet Explorer (tested on v6). 
• Another good workaround is to vary the URL by changing meaningless data in the querystring, e.g. this.  Of course, this also breaks browser-side data-caching, which can be a performance hit.
• Another possible workaround is to somehow suppress the HTTP_CONNECTION header (which defaults to "Keep-Alive").  However, Response.AddHeader("HTTP_CONNECTION", "anything") doesn't work (perhaps because it's a built-in header, and can't be changed?  Ideas are welcome.)
• Another bad workaround is to do the same "grab/store" technique with an ASP (or whatever) session.  This fails as soon as the ASP session times out.

Credits: