socket.io don't run within Azure Emulator

I try to create an Azure WorkerRole with Node.js. This work's without any Problems. If I add socket.io, the Node.js Server don't start if I run in the Emulator. If I start the node.exe with my application JavaScript file, it works.

First I thought, I don't copy the socket.io modules so within the Emulator Node.js could not load the socket.io Module. But I copy all, and the error message shown is not the one, if a module is missing.

The error message on the console looks like this:

...\node_modules\socket.io\lib\Manager.js:104
Server.on<'error', function(err) {
TypeError: Object 12345 has no method 'on'

My Node.js code:

var port = process.env.port || 12345;
var io = require('socket.io').listen(port);
// start socket
io.sockets.on('connection', function (socket) {
    socket.emit('news', { hello: 'world' });

    // create new push session
    socket.on('cid', function (cid) {
        console.log(cid);
    });
});
console.log("Server running at port %d", port);