I got a new notebook some weeks ago and I was unable to connect to the wifi network wih the new machine in Windows XP and Linux. The wifi card in the notebook is a Intel 3945 ABG card. Everything with WPA-PSK.
In Linux I got always (start wpa_cli):
<2>Trying to associate with XX:XX:XX:XX:XX:XX (SSID='NETWORK' freq=0 MHz)
> <2>Associated with XX:XX:XX:XX:XX:XX
> <2>CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
In Windows the Client seems to be associate but no address could be assigned.
All other wifi clients are working fine (Atheros and Broadcom cards).
After weeks of debugging, firmware flashing and tons of google searches I didn't found any solution. I made bugreports to Intel and the Linux distributor but no solutions.
Yesterday I found it!
I simply disabled (because of problem with another Client with Speedbooster card) the Speedbooster of the WRT54GS:
nvram set gmode=1
nvram set afterburner=off
And the last one was the solution. After restarting the AP my new Intel card connects to the AP and everything is working fine.
So if you have similar problems with Intel cards, try to disable afterburner.
I can find a lot of reports with similar problems but this seems to be the first solution for this problem!