10.8.4 Triggering network configuration – waproamd

The waproamd daemon is just like ifplugd except that it is designed to be used with Wi-Fi cards. It actively scans for access points to which the Wi-Fi hardware is able to associate. When association is achieved, waproamd runs ifup.

If you are using waproamd then in general you configure the Wi-Fi card via waproamd and not via wireless-* options in /etc/network/interfaces.