Express & connect-busboy ignore from some requests

I use connect-busboy with express:

var busboy = require('connect-busboy');

app.configure(function () {
    app.use(express.logger());
    app.use(busboy());
    app.use(bodyParser());
    app.use(function(err, req, res, next){
        res.send(500, 'error');
    });

and with the following request:

app.post('/save', function (req, res) { 
       console.log("Got request")
         try {
         console.log("I got it");
         req.pipe(req.busboy);
         var name = "";
         var start = "";
         var fstream;
        req.busboy.on('field', function (fieldname, val, fieldnameTruncated, valTruncated) { }


        req.busboy.on('file', function (fieldname, file) {
           //some code
        }

        req.busboy.on('error', function (error) {
                console.log("Error in uploading file with chunks: "  + error);
            // some code
         })
        req.busboy.on('finish', function () {
               fstream.on('close', function(){
                       //some code
    })
})

the client send me 6 request for save command. I get inconsistently 2-6 requests.

Meaning, Got request is printed only 2 times, but the client send 6 times the request.

When I delete the app.use(busboy()); line, Express.app get the 6 request (but I can't use the function because the req.busboy.on doesn't work).

The conclusion is that app.use(busboy()); ignore some requests from the client, and the app.post isn't fired. How can I solve it?