Directory index seems not to work

[Ferreira Maurizio]

The following program should set directory_index to index.html, 
so that a request as http://127.0.0.1 should return such a file, however
it causes an internal server error.

In the error log file I can see:
   "httpd_file: Can't opend:/temp/"

A request as  http://127.0.0.1/index.html works perfectly.

I'm trying with Erlang R13B, under Windows 2000.

Any suggestion ?
Regards
Maurizio
 
-module(test).
-export([start/0,stop/0]).

start() ->
  inets:start(),
   {ok, Pid} = inets:start(httpd, 
     [ {port, 80},
       {server_name,"ferreira-d"}, 
       {server_root,"d:/temp"},
       {document_root,"d:/temp"}, 
       {directory_index, ["index.html", "welcome.html"]},
       {bind_address, "localhost"},
       {log_format, common},
       {error_log, "errors.log"}, 
       {transfer_log, "transfer.log"}, 
       {security_log, "security.log"}
     ]),
   httpd:info(Pid) .

stop() ->
  inets:stop().