I have a Mac Book Pro and use Android Tether app to tether quite frequently. Here is a copy of the tutorial (Matth3W) I used for the settings:
60. My settings for WiFi tether are...uncheck use Bluetooth, check Enable WiFi Encryption, set up a passphrase (make sure it is 13 characters), change the SSID or leave it default (I left it default), Change channel to 07, power mode active, enable access control unchecked (my preference), change LAN first option, everything else left it the way it was.
The only caveat, when I try to establish the connection, I need to turn on the access control then once connected, I turn it off.
Hope this is helpful.
Mike