Hmmm ... I've always had luck with the madwifi driver for the atheros chipsets. Try this:

sudo rmmod ath_pci
sudo modprobe ath5k

sudo iwlist scan

See if that gives you any more luck.

I also may have asked this already, but what version of Ubuntu are you running, and version of the kernel ? ( uname -r )

david@david-laptop:~$ sudo rmmod ath_pci

[sudo] password for david: 

david@david-laptop:~$ sudo modprobe ath5k

FATAL: Module ath5k not found.

david@david-laptop:~$ sudo iwlist scan

lo        Interface doesn't support scanning.



eth0      Interface doesn't support scanning.



david@david-laptop:~$ uname -r

2.6.24-28-generic

Would you be willing to consider upgrading to a more recent version? I'm assuming you stuck w/ Hardy all this time because it was an LTS release. Ludic is an LTS release, too, and ships with a more modern version of the kernel, and better hardware support. You may find that the upgrade may fix your problem. If you're afraid that Lucid will look too different, might I also suggest that you consider Karmic, as it still has that Ubuntu "human" theme w/ the Orange and brown that you are probably comfortable with. I'm pretty sure that your hardware will work in Karmic, too

"stuck w/ Hardy"? I didn't see any reason to change. Are you implying that I was supposed to upgrade every time they released a new version?

Not necessarily. There's no reason to upgrade, I guess, if everything works fine for you. But clearly, that's not the case.

You're running Kernel 2.6.24, which still relied on madwifi to run the Atheros chipset. That also means that some of the code that runs the software dirven radio in those cards is closed source. Drivers that require cutting a binary from the chip, the downloading of closed source firmware and plugging into the kernel have a lousy track record.

In 2.6.25, the ath5k driver was included in the kernel, which is a completely FOSS driver native to the kernel for the Atheros chipset.

If you absolutely want / need to stick with Hardy, then you may end up needing to patch the madwifi source and re-compiling and re-installing it. Or, you may need to consider rolling your kernel / kpkg to get to the ath5k driver. But frankly, I tihnk in your case upgrading Ubuntu is going to be much easier.