Hi Reza, may you share some code please? Perhaps
http://gist.github.com ?
Here's a working example:
Create user Bruce Wayne.
Then scroll down and choose a file in the s3 section. That will do a "save" immediately.
After that step, click Read User: Bruce Wayne and you'll see the updated s3 link in his field.
What do you mean by s3cmd?
Also, note that we're using underscore-1.3.3 and backbone 0.9.2.
Erick