Module name "http" or "longjohn" has not been loaded yet for context:_ when running in IISNode

I am working on a javascript based app and have started seeing these errors suddenly.

• Message: Module name "http" has not been loaded yet for context: _ http://requirejs.org/docs/errors.html#notloaded

I got the error with Longjohn first (i have the module in my node_modules directory), but when i commented that, it started throwing issues with the next module required, which is "http:.

Other errors I see:

• 'web' is null or not an object - in this line : env.web.protocol

• 'io' is null or not an object - in a simple socketIO connect method.

define(['socket.io'], function(io) {

var socketConnection;

return {
    getConnection: function() { 
        if (! socketConnection) {
            socketConnection = io.connect();
        }
        return socketConnection;
    }
}

All of this works fine under node, but has issues when running under IISNode. I tried simple express and node examples which work fine. I am using Node, IISNode, require.js, backbone and underscore in my project. I am new to javascript, would really appreciate any pointers to fixing this issue