Http Handler and Output Caching

[thinkfr33ly]

Is there any way, either via an ASHX file or lines in a code behind, to
enable output caching for an HTTP Handler?

This is driving me nuts. Nothing I try works. I've tried this in the
ProcessRequest method, but it doesn't appear to do anything:

context.Response.Cache.VaryByParams["*"] = true;
context.Response.Cache.SetExpires(DateTime.Now.Add (Configuration.Settings.OutputHandlerCacheTimeout) );

context.Response.Cache.SetLastModified(DateTime.No w);
context.Response.Cache.SetMaxAge(Configuration.Set tings.OutputHandlerCacheTimeout);
context.Response.Cache.SetCacheability(HttpCacheab ility.Public);
context.Response.Cache.SetValidUntilExpires(true);

Ideas?

Thanks,
RMD