Downloading a file in results (view or edit) will change name and extension

Hi,

I have a webform which has a file field. Everything works except that files with extensions tar.gz, bz, or tgz are not downloaded correctly. The file Field accepts the previous extensions, plus zip. Files are saved as private, and served by drupal (settings under "admin/config/media/file-system").

Users with right to view and edit files can access the "view" and "edit" links under the "results" tab, and they are shown the form, which includes the previously uploaded file. If the file is in zip format, they are able to download it (although the file name will be changed to a randomly array of characters). This is not the exact desired behavior, but al least they download the file with the correct extension. But if the file is in tar.gz, bz, or tgz, the browser prompts to save a "", the file name is changed to a random array of characters, and in a windows computer they pretty much download a file they cannot use until they rename it and add an extension)

What I need is for these files to be downloaded with the same name they have under the drupal file system (which is correctly displayed on the url)