How do I cache at both client & server when VaryByParam != "none"?

Question

I'm looking for a way to cache a page at both the client and the server while varying the server's output cache by a querystring parameter "Version".

With this tag:

<%@ OutputCache Duration="10" Location="Any" VaryByParam="none" %>

I get these headers:

HTTP/1.1 200 OK
Cache-Control: public
Content-Type: text/html; charset=utf-8
Expires: Wed, 03 Feb 2010 02:29:24 GMT
Last-Modified: Wed, 03 Feb 2010 02:29:14 GMT
Server: Microsoft-IIS/7.5
X-AspNet-Version: 4.0.21006
X-Powered-By: ASP.NET
Date: Wed, 03 Feb 2010 02:29:14 GMT
Content-Length: 2364

This does exactly what I want on the client side, but on the server side it doesn't vary by "Version".

Meanwhile, with this tag:

<%@ OutputCache Duration="10" Location="Any" VaryByParam="Version" %>

I get these headers:

HTTP/1.1 200 OK
Cache-Control: public, max-age=4
Content-Type: text/html; charset=utf-8
Expires: Wed, 03 Feb 2010 02:28:29 GMT
Last-Modified: Wed, 03 Feb 2010 02:28:19 GMT
Vary: *
Server: Microsoft-IIS/7.5
X-AspNet-Version: 4.0.21006
X-Powered-By: ASP.NET
Date: Wed, 03 Feb 2010 02:28:25 GMT
Content-Length: 2352

This does exactly what I want on the server side, but the "Vary: *" header forces the browser to reload the page on every request.

Is there any way to get caching on both the client and server side while varying by a parameter?

Answer 1

Found it:

protected void Page_Load(object sender, EventArgs e)
{
  Response.Cache.SetOmitVaryStar(true);
}

More info here: http://support.microsoft.com/kb/836868

Supposedly this has been fixed for ASP.NET 4 beta 2 (see http://www.asp.net/learn/whitepapers/aspnet4/breaking-changes/#_TOC10) but it still seems broken as of VS 2010 RC.