Hi Ardalan,
If replace the method to "CopyTo", does it work? Is your site online? If so, can you set up ftp access for us? So we can check the code for you directly.
Try save the files in the handler file "UploadHandler.ashx" directly, does it work?
the handler file has a method "public override void OnFileUploaded(MvcUploadFile file)", you can save the file there.
Regards,
Ken