Metabase, CacheControlCustom and ASPNET 2.0

[Will Holley]

I have a problem with cache headers which I cannot track down. We are running
IIS6 on Windows Server 2003 and ASP.NET 2.0.

Our application has an installer which sets up our caching options in the
metabase - specifically it sets HttpExpires="D, 0" and
CacheControlCustom="no-cache" on the directory containing our web forms. In
IIS manager this shows up correctly (saying expires immediately).

For some specific web forms (aspx) within this directory we set explicit
values for HttpExpires and CacheControlCustom. These appear to work
correctly.

The problem is that the aspx pages which do not have explicit entries in the
metabase do not seem to inherit the cache settings from their parent
directory. These come out of IIS as having CacheControlCustom="private"
instead of "no-cache" as defined in the metabase.

Does anybody have any idea what might be causing this behaviour? I
understand that ASPNET gives aspx pages a default cachecontrol value of
private but how does this interact with the IIS metabase settings (does the
metabase setting get read in before the page is processed or after ASPNET has
produced it's output)?

One solution I can think of would be to set this programmatically for all
our aspx pages (which inherit from a base class) in ASPNET but how can I do
this while allowing the metabase cachecontrol to persist?

Many thanks for help on this issue!