These are the steps that I will usually take.. I am using a netgear card
Once that is done you should be in both monitor mode and with a fake mac. Hope this helps. FWIW I think I might be doing a bit of overkill on my steps but no big deal to me. If you do not want to switch to monitor mode, leave out steps 1, 2, 4, 6, & 7. Remember though that there have been people out there having issues with fake mac addresses...wlanconfig ath0 destroy
airmon-ng start wifi0
ifconfig ath0 down
ifconfig wifi0 down
macchanger ath0 -m 00:11:22:33:44:55
macchanger wifi0 -m 00:11:22:33:44:55
ifconfig wifi0 up
ifconfig ath0 up
for this issue, I found the following by Xploitz:
[EDIT] My post count is not high enough yet... search for the following by him...
-=Xploitz=- Tutorial: E-Z Atheros FAKED MAC Internet Connection!