I have a dual boot OS/X and Feisty on my Macbook C2D. Everything was working perfectly up until the point where I needed to enable wireless networking in Linux (makes it easier to follow lectures in class, etc.)

So I read up on the latest madwifi drivers, see that they finally support the new Atheros chips in the C2D, I download the latest snapshot, install it, and everything seems to be running smoothly. I sudo modprobe ath_pci after installing, and the entire system freezes. I wait about 10 minutes, and then hard reboot the computer. But now, Ubuntu won't even boot. It gets about 1/6 of the way through the status bar, and then stops. This has happened twice already, and I've had to reinstall Ubuntu both times.

What could be causing this freeze?

Couple of things you should do:

- Verify that Ubuntu is really frozen (=totally unresponsive) during the boot. It might just be doing something which takes very long. Or some service is not responding and is not timing out.

- Disable Atheros drivers in one of these ways:
1) boot into recovery mode (probably ESC during boot, and select "Single user mode" from the Grub/Lilo menu), remove the Atheros modules
2) boot with a LiveCD (Knoppix/Ubuntu/whatever), mount you HD and remove the Atheros modules

- Try a different version of the Madwifi drivers when you've uninstalled the previous ones and the system boots again
- Disable the bootsplash (the Ubuntu logo) during boot, so that you can actually see what's happening (see /boot/grub/menu.lst if using grub)