I have a USB WiFi adapter, D-Link dwl-g122. I'm running Ubuntu 10.4. My laptop has a built-in wireless card that is connecting fine to the router. I plug in the usb and it never really connects. Here are some details:

iwconfig

wlan1     IEEE 802.11bg  ESSID:"\x0B\xE1..."  
          Mode:Managed  Frequency:2.457 GHz  Access Point: Not-Associated   
          Tx-Power=19 dBm   
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Power Management:on

lshw -c network:

  *-network:1
       description: Wireless interface
       physical id: 3
       logical name: wlan1
       serial: 00:13:46:8b:xx:xx
       capabilities: ethernet physical wireless
       configuration: broadcast=yes multicast=yes wireless=IEEE 802.11bg

dmesg

[ 1096.814176] wlan1: direct probe to AP xxx (try 1)
[ 1096.820960] wlan1: direct probe responded
[ 1096.820969] wlan1: authenticate with AP xxx (try 1)
[ 1096.823790] wlan1: authenticated
[ 1096.823869] wlan1: associate with AP xxx (try 1)
[ 1096.827667] wlan1: RX AssocResp from xxx (capab=0x411 status=0 aid=1)
[ 1096.827674] wlan1: associated
[ 1142.590912] wlan1: deauthenticating from xxx by local choice (reason=3)

lsmod|rt2

rt2500usb              19643  0 
rt2x00usb              11260  1 rt2500usb
rt2x00lib              32133  2 rt2500usb,rt2x00usb
mac80211              238896  3 ath5k,rt2x00usb,rt2x00lib
cfg80211              148725  4 ath5k,ath,rt2x00lib,mac80211
led_class               3764  3 ath5k,rt2x00lib,sdhci

It looks like the driver loads but it doesn't feel like connecting. The behavior is identical even if I blacklist the other wifi card (using an ath5k driver). It's almost like it is using the wrong password or something. Does anyone know what is happening? Is anyone using Ubuntu successful?