Service Unavailable - JWchat with Ejabberd, on Windows IIS

I installed JWChat on Windows, with IIS,
following the instructions from this tutorial http://www.ejabberd.im/jwchat (step 1-4).
Step 5 I got ISAPI filter following this link http://www.ejabberd.im/node/379#comment-911. Applied that to my localhost.
Then installed Ejabberd (downloaded the windows package, installer Erlang, OpenSSL first).

Now Ejabberd runs as a service, I can connect from Gaim to my local Ejabberd server.
But when I go to here, http://localhost/jwchat/index.html (IE), I can see the login page.
Enter ID/pwd, register, the Jwchat roster window pops up. Then I see a "Service Unavailable" error pop up.

I think the http-poll for Jwchat to Ejabberd is not working.
I have been looking through the forum. There are a few questions like mine that remain unanswered.
Please help! Thanks in advance.

===================================================================================
My ejabberd.cfg is the default one, just changed the host name.
The config.cs for Jwchat is:
var SITENAME = "jding";
var DEFAULTRESOURCE = "jwchat";
var BACKENDS =
[
{
name:"Ejabberd",
description:"Ejabberd's native HTTP Polling backend",
httpbase:"http-poll/",
type:"polling",
servers_allowed: [SITENAME]
},
];

var timerval = 2000; // poll frequency in msec

var stylesheet = "jwchat.css";
var THEMESDIR = "themes";

/* DEFAULTCONFERENCEGROUP + DEFAULTCONFERENCESERVER
* default values for joingroupchat form
*/
var DEFAULTCONFERENCEROOM = "talks";
var DEFAULTCONFERENCESERVER = "conference.localhost";

/* debugging options */
var DEBUG = false; // turn debugging on
var DEBUG_LVL = 2; // debug-level 0..4 (4 = very noisy)

var USE_DEBUGJID = true; // if true only DEBUGJID gets the debugger
var DEBUGJID = "admin@localhost"; // which user get's debug messages