I suspect that there's something fishy about your card. Do you have any other
Atheros card for testing?
If you want to try Debian testing (semi-rolling) or unstable (rolling), go to
Developers' Corner -> Debian Installer, and then pick an appropriate image
for you. (You may probably need to use the amd64-architecture, weekly-built
DVD image.)
The installer image I use is updated every week, and I don't download the
iso-format image. Instead, I use jigdo to update the image incrementally. So
I don't download it via any URL. Follow the instructions on the Debian
Installer page if you want to give it a try.
Finally, Debian Live images are not designed as installation media. They
focus on globalization support (i.e., they contain lots of language packages
which you probably won't need), so they are big in size but contain
(relatively) very few software packages. Use binary installation media
instead.
