MAC address change

[Mustafa C. Kuscu]

When I change the wireless NIC's MAC address using SIOCSIFHWADDR 
ioctl(), the card associates to the AP using the new MAC (but it does 
not send disassociation).

Is this because of the hostap driver, or the firmware? More 
specifically, to what extent can I control the procedure that the 
ioctl() initiates such that those excessive associations can be 
eliminated?

Thanks,
Mustafa