Unfortunately, the fix does not work for me. First, to be sure I'm using the correct version, 'dpkg -l | grep wpa' gives this:

ii  wpagui                                 0.7.3-6ubuntu2.1                             graphical user interface for wpa_supplicant
ii  wpasupplicant                          0.7.3-6ubuntu2.1                             client support for WPA and WPA2 (IEEE 802.11i)

The first time I rebooted after installing from proposed, connection was successful. Every subsequent attempt failed, whether after resuming from a suspend or after a reboot.  I get into an endless loop of password requests. Here is a log extract for the last attempt:

Oct  8 09:49:32 foo NetworkManager[987]: get_secret_flags: assertion `is_secret_prop (setting, secret_name, error)' failed
Oct  8 09:49:32 foo NetworkManager[987]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) scheduled...
Oct  8 09:49:32 foo NetworkManager[987]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) started...
Oct  8 09:49:32 foo NetworkManager[987]: <info> (wlan0): device state change: need-auth -> prepare (reason 'none') [60 40 0]
Oct  8 09:49:32 foo NetworkManager[987]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) scheduled...
Oct  8 09:49:32 foo NetworkManager[987]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) complete.
Oct  8 09:49:32 foo NetworkManager[987]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) starting...
Oct  8 09:49:32 foo NetworkManager[987]: <info> (wlan0): device state change: prepare -> config (reason 'none') [40 50 0]
Oct  8 09:49:32 foo NetworkManager[987]: <info> Activation (wlan0/wireless): connection 'Northwestern' has security, and secrets exist.  No new secrets needed.
Oct  8 09:49:32 foo NetworkManager[987]: <info> Config: added 'ssid' value 'Northwestern'
Oct  8 09:49:32 foo NetworkManager[987]: <info> Config: added 'scan_ssid' value '1'
Oct  8 09:49:32 foo NetworkManager[987]: <info> Config: added 'key_mgmt' value 'WPA-EAP'
Oct  8 09:49:32 foo NetworkManager[987]: <info> Config: added 'password' value '<omitted>'
Oct  8 09:49:32 foo NetworkManager[987]: <info> Config: added 'eap' value 'PEAP'
Oct  8 09:49:32 foo NetworkManager[987]: <info> Config: added 'fragment_size' value '1300'
Oct  8 09:49:32 foo NetworkManager[987]: <info> Config: added 'phase2' value 'auth=MSCHAPV2'
Oct  8 09:49:32 foo NetworkManager[987]: <info> Config: added 'identity' value 'xyz'
Oct  8 09:49:32 foo NetworkManager[987]: <info> Config: added 'bgscan' value 'simple:30:-45:300'
Oct  8 09:49:32 foo NetworkManager[987]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) complete.
Oct  8 09:49:32 foo NetworkManager[987]: <info> Config: set interface ap_scan to 1
Oct  8 09:49:32 foo NetworkManager[987]: <info> (wlan0): supplicant interface state: disconnected -> scanning
Oct  8 09:49:35 foo wpa_supplicant[1252]: Trying to authenticate with d8:c7:aa:bb:cc:dd (SSID='Northwestern' freq=2412 MHz)
Oct  8 09:49:35 foo kernel: [   81.192887] wlan0: direct probe to d8:c7:aa:bb:cc:dd (try 1/3)
Oct  8 09:49:35 foo NetworkManager[987]: <info> (wlan0): supplicant interface state: scanning -> authenticating
Oct  8 09:49:35 foo kernel: [   81.390976] wlan0: direct probe to d8:c7:aa:bb:cc:dd (try 2/3)
Oct  8 09:49:35 foo kernel: [   81.590735] wlan0: direct probe to d8:c7:aa:bb:cc:dd (try 3/3)
Oct  8 09:49:36 foo kernel: [   81.790410] wlan0: direct probe to d8:c7:aa:bb:cc:dd timed out
Oct  8 09:49:44 foo wpa_supplicant[1252]: Trying to authenticate with d8:c7:aa:bb:cc:dd (SSID='Northwestern' freq=2412 MHz)
Oct  8 09:49:44 foo kernel: [   89.988028] wlan0: authenticate with d8:c7:aa:bb:cc:dd (try 1)
Oct  8 09:49:44 foo kernel: [   89.990422] wlan0: d8:c7:aa:bb:cc:dd denied authentication (status 17)