Lighttpd

mod_expires must be defined before mod_ssi if you want mod_ssi to properly
set expire headers. This should be mentioned in the boring manual.

Currently the documentation reads:

the order of the modules is somewhat important as the modules are
    handled in the way they are specified. mod_rewrite should always be the first module, mod_accesslog always the last.

e.g.:

server.modules          = ( "mod_rewrite", 
                            "mod_redirect", 
                            "mod_alias",
                            "mod_access", 
                            "mod_auth", 
                            "mod_status", 
                            "mod_fastcgi",
                            "mod_proxy",
                            "mod_simple_vhost",
                            "mod_evhost",
                            "mod_userdir",
                            "mod_cgi",
                            "mod_compress",
                            "mod_ssi",
                            "mod_usertrack",
                            "mod_expire",
                            "mod_secdownload",
                            "mod_rrdtool",
                            "mod_accesslog" )

This is somewhat misleading in that mod_ssi is required after mod_expires, but actually needs to be defined before mod_expires. Either reordering this list or adding a note would elevate confusion.

-- buecking