Comment 13 for bug 105637

Actually there is a possible quickaround I found a couple of weeks ago, however it may not be battery friendly since the wireless will remain always on.

For all of you that have issues with NetworkManager and their madwifi wireless card, try load the ath_pci with rfkill=0 and see if it works for you.
meaning:
sudo rmmod ath_pci #to unload the ath_pci
sudo modprobe ath_pci rfkill=0 #load the ath_pci module