Wireless authentication times out with ureadahead and ath9k on 64 bit Ubuntu 11.04

[David]

In trying to diagnose a problem with wireless authentication (nm-applet asks for password, wicd says "bad password") for a new TP-Link WN951N PCI wireless card (native kernel driver is ath9k), I found that purging the ureadahead package solved my problems. I am running Ubuntu 11.04 amd64 on a SSD as my main system (shouldn't ureadahead be removed by default on SSDs?).

The Ubuntu 10.10 and 11.04 32 bit live CDs could connect no worries, but the Ubuntu 11.04 64 bit live CD produces the same problem for me.

Before testing with the live CDs I had tried updating/downgrading the kernel several times (even to version 3.0.0-0300rc6), changing encryption, password, and channel -- all with no success. Loading wireshark I noticed that whilst I could scan correctly for my modem/router, no packets were actually being set or received. After purging ureadahead and rebooting (several times to make sure it works) I can now see the packets being exchanged in authentication and it all works as expected.

The output of dmesg | grep ath was a constant loop of:
[<time>] wlan0: associate with xx:xx:xx:xx:xx:xx (try 1)
[<time>] wlan0: associate with xx:xx:xx:xx:xx:xx (try 2)
[<time>] wlan0: associate with xx:xx:xx:xx:xx:xx (try 3)
[<time>] wlan0: association with xx:xx:xx:xx:xx:xx timed out