Comment 5 for bug 62106

I have the same error on a clean install.

lspci:
01:06.0 Ethernet controller: Atheros Communications, Inc. AR5212 802.11abg NIC (rev 01)

iwconfig:
ath0 IEEE 802.11g ESSID:"VE"
          Mode:Managed Frequency:2.437 GHz Access Point: Not-Associated
          Bit Rate:0 kb/s Tx-Power:18 dBm Sensitivity=0/3
          Retry:off RTS thr:off Fragment thr:off
          Power Management:off
          Link Quality=0/94 Signal level=-95 dBm Noise level=-95 dBm
          Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
          Tx excessive retries:0 Invalid misc:0 Missed beacon:0

rpereira@joaopaulo2:~$ sudo iwconfig ath0 mode master
Error for wireless request "Set Mode" (8B06) :
    SET failed on device ath0 ; Invalid argument.
rpereira@joaopaulo2:~$ sudo iwconfig ath0 mode Master
Error for wireless request "Set Mode" (8B06) :
    SET failed on device ath0 ; Invalid argument.

I have D-Link DWL520 Rev. B3.