I am running the ALFA AWUS036H on BT4 and I am able to crack WEP etc. However I cannot connect to my AP. I get the following:

Error for wireless request "Set ESSID" (8B1A) :
    SET failed on device wlan0 ; Operation not supported.

I have searched for the error over at remote-exploit and tried the suggestions without success. Any ideas?

# iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

wmaster0  no wireless extensions.

wlan0     IEEE 802.11bg  Mode:Monitor  Frequency:2.442 GHz  Tx-Power=27 dBm
          Retry min limit:7   RTS thr:off   Fragment thr=2352 B
          Encryption key:off
          Power Management:off
          Link Quality:0  Signal level:0  Noise level:0
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

# iwconfig wlan0 mode managed
Error for wireless request "Set Mode" (8B06) :
    SET failed on device wlan0 ; Device or resource busy.

wlanconfig wlan0 destroy
wlanconfig: ioctl: Operation not supported

I am using the rtl8187 drivers. Now that you mention it I may have been using airmon when I tried to connect. I will try again.

Thanks for the help. Appreciate it..........