atheros wireless is highly unstable

Originally reported as part of bug 710711 (that bug is about nm-applet, and has been fixed afaict), this bug is solely about the flakiness of the atheros wireless support in my MBP1,1. After a clean reboot, the machine connects to my preferred ssid just fine. It will remain up for anywhere from a minute or so to several hours, then it crashes. Once crashed, there's no way to reconnect to the wireless, and scanning does not see any ssids. The workaround is to shutdown, disconnect power and battery, reboot to osx, then reboot to ubuntu.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: linux-image-2.6.38-4-generic 2.6.38-4.31
Regression: Yes
Reproducible: No
ProcVersionSignature: Ubuntu 2.6.38-4.31-generic 2.6.38-rc5
Uname: Linux 2.6.38-4-generic i686
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: barry 1732 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0x98400000 irq 46'
   Mixer name : 'SigmaTel STAC9221 A1'
   Components : 'HDA:83847680,106b0200,00103401'
   Controls : 20
   Simple ctrls : 12
Date: Wed Feb 23 11:42:03 2011
EcryptfsInUse: Yes
Frequency: Once a day.
HibernationDevice: RESUME=UUID=2133112d-ee2e-4263-87c3-c053d3c1b408
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Beta i386 (20100318)
MachineType: Apple Computer, Inc. MacBookPro1,1
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, user)
 LANG=en_US.UTF-8
 LC_MESSAGES=en_US.utf8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-4-generic root=UUID=c4eaec52-5c0b-414f-8060-cc47b9c9fd1a ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-2.6.38-4-generic N/A
 linux-backports-modules-2.6.38-4-generic N/A
 linux-firmware 1.47
SourcePackage: linux
dmi.bios.date: 10/12/06
dmi.bios.vendor: Apple Computer, Inc.
dmi.bios.version: MBP11.88Z.0055.B08.0610121325
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: Mac-F425BEC8
dmi.board.vendor: Apple Computer, Inc.
dmi.board.version: PVT
dmi.chassis.asset.tag: Asset Tag
dmi.chassis.type: 8
dmi.chassis.vendor: Apple Computer, Inc.
dmi.chassis.version: Mac-F425BEC8
dmi.modalias: dmi:bvnAppleComputer,Inc.:bvrMBP11.88Z.0055.B08.0610121325:bd10/12/06:svnAppleComputer,Inc.:pnMacBookPro1,1:pvr1.0:rvnAppleComputer,Inc.:rnMac-F425BEC8:rvrPVT:cvnAppleComputer,Inc.:ct8:cvrMac-F425BEC8:
dmi.product.name: MacBookPro1,1
dmi.product.version: 1.0
dmi.sys.vendor: Apple Computer, Inc.