Problem with save()

Hi guys, first of all my apologies if i ask some newbie question but i have this problem and i can't find a solution for that.
I've flashed my esp-12 with the latest firmware (thanks tve) and and if i try to save my code adding save(), the web IDE return erasing flash... writing... compressed byte (numbers) bytes to (numbers) but it hasn't saved nothing, just erased the flash.
I've tried only to send an the http server example:

var http = require("http");
http.createServer(function (req, res) {
res.writeHead(200);
res.end("Hello World");
}).listen(8080);

and it works but just adding save() at the end of the code, erase the flash but the code don't work.
What i'm doing wrong?
Thanks for your time guys
Marco