WPA Personal worked fine for me in Hardy, and has ceased to work with the Intrepid upgrade.  I tried the PPA repository posted above, but that doesn't make things better.

Kernel: Linux fortrock 2.6.27-7-generic #1 SMP Tue Nov 4 19:33:20 UTC 2008 i686 GNU/Linux

Wifi chipset: 0b:00.0 Network controller: Intel Corporation PRO/Wireless 3945ABG [Golan] Network Connection (rev 02)

Lots of this in dmesg:

[  193.599589] eth1: associated
[  203.785117] eth1: disassociating by local choice (reason=3)
[  207.415441] eth1: authenticate with AP 00:17:9a:f1:06:35
[  207.417208] eth1: authenticated
[  207.417218] eth1: associate with AP 00:17:9a:f1:06:35
[  207.418981] eth1: authenticate with AP 00:17:9a:f1:06:35
[  207.420705] eth1: authenticated
[  207.420721] eth1: associate with AP 00:17:9a:f1:06:35
[  207.423204] eth1: RX ReassocResp from 00:17:9a:f1:06:35 (capab=0x431 status=0 aid=1)
[  207.423213] eth1: associated
[  214.097706] eth1: disassociating by local choice (reason=3)

Syslog:

Nov 12 23:54:40 fortrock kernel: [  138.348143] eth1: authenticated
Nov 12 23:54:40 fortrock kernel: [  138.348152] eth1: associate with AP 00:17:9a:f1:06:35
Nov 12 23:54:40 fortrock kernel: [  138.350460] eth1: RX ReassocResp from 00:17:9a:f1:06:35 (capab=0x431 status=0 aid=1)
Nov 12 23:54:40 fortrock kernel: [  138.350468] eth1: associated
Nov 12 23:54:40 fortrock NetworkManager: <info>  (eth1): supplicant connection state change: 3 -> 4 
Nov 12 23:54:40 fortrock NetworkManager: <info>  (eth1): supplicant connection state change: 4 -> 5 
Nov 12 23:54:50 fortrock NetworkManager: <info>  (eth1): supplicant connection state change: 5 -> 0 
Nov 12 23:54:50 fortrock NetworkManager: <info>  (eth1): supplicant connection state change: 0 -> 2 
Nov 12 23:54:50 fortrock kernel: [  148.532151] eth1: disassociating by local choice (reason=3)
Nov 12 23:54:50 fortrock NetworkManager: <info>  (eth1): supplicant connection state change: 2 -> 0 
Nov 12 23:54:51 fortrock NetworkManager: <info>  eth1: link timed out. 
Nov 12 23:54:54 fortrock NetworkManager: <info>  (eth1): supplicant connection state change: 0 -> 3 
Nov 12 23:54:54 fortrock kernel: [  152.154813] eth1: authenticate with AP 00:17:9a:f1:06:35
Nov 12 23:54:54 fortrock kernel: [  152.158098] eth1: authenticate with AP 00:17:9a:f1:06:35
Nov 12 23:54:54 fortrock kernel: [  152.158133] eth1: authenticated
Nov 12 23:54:54 fortrock kernel: [  152.158136] eth1: associate with AP 00:17:9a:f1:06:35
Nov 12 23:54:54 fortrock NetworkManager: <info>  (eth1): supplicant connection state change: 3 -> 4 
Nov 12 23:54:54 fortrock kernel: [  152.164600] eth1: RX ReassocResp from 00:17:9a:f1:06:35 (capab=0x431 status=0 aid=1)
Nov 12 23:54:54 fortrock kernel: [  152.164607] eth1: associated
Nov 12 23:54:54 fortrock NetworkManager: <info>  (eth1): supplicant connection state change: 4 -> 5 
Nov 12 23:55:04 fortrock kernel: [  162.349149] eth1: disassociating by local choice (reason=3)
Nov 12 23:55:04 fortrock NetworkManager: <info>  (eth1): supplicant connection state change: 5 -> 0 
Nov 12 23:55:04 fortrock NetworkManager: <info>  (eth1): supplicant connection state change: 0 -> 2 
Nov 12 23:55:04 fortrock NetworkManager: <info>  (eth1): supplicant connection state change: 2 -> 0 
Nov 12 23:55:08 fortrock kernel: [  165.971313] eth1: authenticate with AP 00:17:9a:f1:06:35
Nov 12 23:55:08 fortrock kernel: [  165.973078] eth1: authenticated
Nov 12 23:55:08 fortrock NetworkManager: <info>  (eth1): supplicant connection state change: 0 -> 3 
Nov 12 23:55:08 fortrock kernel: [  165.973087] eth1: associate with AP 00:17:9a:f1:06:35
Nov 12 23:55:08 fortrock kernel: [  165.975648] eth1: authenticate with AP 00:17:9a:f1:06:35
Nov 12 23:55:08 fortrock kernel: [  165.977395] eth1: authenticated
Nov 12 23:55:08 fortrock kernel: [  165.977404] eth1: associate with AP 00:17:9a:f1:06:35
Nov 12 23:55:08 fortrock NetworkManager: <info>  (eth1): supplicant connection state change: 3 -> 4 

/var/log/wpa_supplicant:

Trying to associate with 00:17:9a:f1:06:35 (SSID='dedasys' freq=2437 MHz)
Associated with 00:17:9a:f1:06:35
Authentication with 00:17:9a:f1:06:35 timed out.
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
CTRL-EVENT-SCAN-RESULTS 
Trying to associate with 00:17:9a:f1:06:35 (SSID='dedasys' freq=2437 MHz)
Associated with 00:17:9a:f1:06:35
Authentication with 00:17:9a:f1:06:35 timed out.
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
CTRL-EVENT-SCAN-RESULTS 
Trying to associate with 00:17:9a:f1:06:35 (SSID='dedasys' freq=2437 MHz)
Associated with 00:17:9a:f1:06:35
CTRL-EVENT-SCAN-RESULTS 
Authentication with 00:17:9a:f1:06:35 timed out.
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys

For comparison, here's what things looked like in Hardy, when they worked:

Nov 10 16:08:05 fortrock kernel: [30142.683714] eth1: No ProbeResp from current AP 00:17:9a:f1:06:35 - assume out of range
Nov 10 16:08:26 fortrock kernel: [30163.618193] eth1: Initial auth_alg=0
Nov 10 16:08:26 fortrock kernel: [30163.618199] eth1: authenticate with AP 00:17:9a:f1:06:35
Nov 10 16:08:26 fortrock kernel: [30163.619926] eth1: RX authentication from 00:17:9a:f1:06:35 (alg=0 transaction=2 status=0)
Nov 10 16:08:26 fortrock kernel: [30163.619931] eth1: authenticated
Nov 10 16:08:26 fortrock kernel: [30163.619934] eth1: associate with AP 00:17:9a:f1:06:35
Nov 10 16:08:26 fortrock kernel: [30163.622214] eth1: Initial auth_alg=0
Nov 10 16:08:26 fortrock kernel: [30163.622217] eth1: authenticate with AP 00:17:9a:f1:06:35
Nov 10 16:08:26 fortrock kernel: [30163.622225] eth1: RX authentication from 00:17:9a:f1:06:35 (alg=0 transaction=2 status=0)
Nov 10 16:08:26 fortrock kernel: [30163.622226] eth1: authenticated
Nov 10 16:08:26 fortrock kernel: [30163.622228] eth1: associate with AP 00:17:9a:f1:06:35
Nov 10 16:08:26 fortrock kernel: [30163.623921] eth1: authentication frame received from 00:17:9a:f1:06:35, but not in authenticate state - ignored
Nov 10 16:08:26 fortrock kernel: [30163.626274] eth1: RX ReassocResp from 00:17:9a:f1:06:35 (capab=0x431 status=0 aid=2)
Nov 10 16:08:26 fortrock kernel: [30163.626278] eth1: associated
Nov 10 16:08:26 fortrock kernel: [30163.626289] eth1: switched to short barker preamble (BSSID=00:17:9a:f1:06:35)
Nov 10 16:08:26 fortrock kernel: [30163.661159] eth1: deauthenticate(reason=3)
Nov 10 16:08:27 fortrock kernel: [30164.126318] eth1: RX deauthentication from 00:17:9a:f1:06:35 (reason=6)
Nov 10 16:08:27 fortrock kernel: [30164.126322] eth1: deauthenticated
Nov 10 16:08:28 fortrock kernel: [30165.124593] eth1: direct probe to AP 00:17:9a:f1:06:35 try 1
Nov 10 16:08:28 fortrock kernel: [30165.126969] eth1 direct probe responded
Nov 10 16:08:28 fortrock kernel: [30165.126973] eth1: authenticate with AP 00:17:9a:f1:06:35
Nov 10 16:08:28 fortrock kernel: [30165.128677] eth1: RX authentication from 00:17:9a:f1:06:35 (alg=0 transaction=2 status=0)
Nov 10 16:08:28 fortrock kernel: [30165.128680] eth1: authenticated
Nov 10 16:08:28 fortrock kernel: [30165.128682] eth1: associate with AP 00:17:9a:f1:06:35
Nov 10 16:08:28 fortrock kernel: [30165.328245] eth1: associate with AP 00:17:9a:f1:06:35
Nov 10 16:08:28 fortrock kernel: [30165.527892] eth1: associate with AP 00:17:9a:f1:06:35
Nov 10 16:08:29 fortrock kernel: [30165.727542] eth1: association with AP 00:17:9a:f1:06:35 timed out
Nov 10 16:08:32 fortrock kernel: [30169.416090] eth1: Initial auth_alg=0
Nov 10 16:08:32 fortrock kernel: [30169.416095] eth1: authenticate with AP 00:17:9a:f1:06:35
Nov 10 16:08:32 fortrock kernel: [30169.417832] eth1: RX authentication from 00:17:9a:f1:06:35 (alg=0 transaction=2 status=0)
Nov 10 16:08:32 fortrock kernel: [30169.417836] eth1: authenticated
Nov 10 16:08:32 fortrock kernel: [30169.417838] eth1: associate with AP 00:17:9a:f1:06:35
Nov 10 16:08:32 fortrock kernel: [30169.420060] eth1: RX AssocResp from 00:17:9a:f1:06:35 (capab=0x431 status=0 aid=2)
Nov 10 16:08:32 fortrock kernel: [30169.420065] eth1: associated
Nov 10 16:08:32 fortrock kernel: [30169.420072] eth1: switched to short barker preamble (BSSID=00:17:9a:f1:06:35)
Nov 10 16:08:32 fortrock kernel: [30169.420788] ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready