HiDownload file extentions

Maybe a stupid question but
downloading Quicktime streams with HiDownload results in
three files with different extensions.
Please tell me what sort of file is that with the extension: .hdr
and what kind is that with: .@@@ ???

You can read about .hdr files on the following web-page
HDR file extension

.@@@ is a temporary file of HiDownload.

If you have problems recording some particular stream, just post the URL of a web-page where we can find it.